This is a huge project…
Good landing.
What have you worked with so far, sounds like this is your first big project?
Do you have some equipment today, or previous experience?
Some of this tools you don’t learn over night.
What is your main target?
Except earning money 
Fast and easy?
Acceptably quality?
Good Quality?
Nice workflow?
Large MP spheres?
Awesome spheres?
Next big pieces in the puzzle are;
Access to area when it’s closed?
Is it close to where you live/work?
What time of the day is this going to happen?
Is it a constant movement in the area?
How is the lightning, do you require a high dynamic camera rig? Indoor with a lot of windows and strong lights?
Odd but very important information, how is the mobile internet plans in the country, if it’s unlimited with full speed, great, if not, we have a problem.
Why I’m taking this is up, 1200 pic is a lot of MB for any mobile internet plan, and those are your main viewers.
Don’t fixate on large MP solutions, focus on creating clear noiseless pictures.
I noticed that 100MP spheres show up better on map in crowded areas, but if this are the only spheres in the area, 32-36MP is a smoother option.
With all this in mind, let’s go through a few of your options.
Theta V;
Very easy to work with, need no experience.
Effective time capture 1200 spheres ~3.5h (~10h with HDR), leveling not required.
Photos are just below OK in quality and ready to publish.
Great for areas where it’s crowded and a lot of movement, get a 3-5 meter light tripod. Amazing result as long as light is balanced.
Easy to work with, I would check every pic before uploading them and remove tripod, it’s less then 1 minute with PTGui and photoshop.
It is OK to leave tripod without edit when you shoot from 3-5 meter above, hardly visible and peoples movement is not going to bother you for 1 sec during shooting. ← this is very important facts.
In areas with a lot of movement you shoot without HDR, every pic take less then 10 sec, ~1 minute with HDR.
Downfall with no HDR, only good for even lit areas.
If area is free of movement, either HDR or bracketing(Not shore if the V support bracketing, not used it yet).
Battery life sux, but can be upgraded with a external USB battery pack.
Overheating, here it might have a problem if you work fast.
Works in your favor if you’re a smoker and need a break now and then.
Can be used in combination with a DSLR where quality is not required, where a lot of photos is required.
IRIS 360;Example
This rig has it’s limits in speed capturing photos, 5 sec to snap a sphere and 60sec of stiching.
Effective time capture 1200 spheres ready for upload after ~20h.
During inside camera stiching you can move it to next locaton and level it, very useful.
I find the noise in pictures a bit annoying for this priceclass.
Photos are OK, not superb, leaves a bit of a footprint at nadir, gives me mixed feelings for this solution.
It sounds good on paper, but is it?
Footprint could be used in a commercial purpose with logo or other info, be creative here, camera has a few good options here, as they noticed this flaw and tried to fix it.
As a viewer if would be annoyed after the 10th picture with a logo at nadir, can you imagine after 1200 pictures.
If nicer footprint is required, a lot of time could be lost here.
Batter life 6-8h, use replacable batteries.
It has it’s niche, are you in it, I think so?
If area has nice mountains and great views in the far, this camera might not do a good job.
D7200 Sigma 8mm;
Takes a while to get into the flow, when you get there, you never think of a 1 snap camera again.
Effective time capture 1200 spheres ~5h, excluding moving camera and level it.
Editing time ~ 250h (~30 days), if it’s not a well paid job, this is not the kit for you.
A sloppy batch editing can be done in 20h, but then IRIS is a better option.
I really don’t notice much of a time differance in editing 3, 5, 7, 9 leveled bracketed images, only result is visible advantages.
Don’t use a zoom lens, calibration will be off and you might have to spend hours fixing alignment or reshoot a lot of pictues.
Photo quality is excellent. Captures ~72MP/25MB, but can be rendered at either 50MP/20MB or 32MP/3MB without noticeable differance, if size do matter.
If lightning is bad, it has a 9 level bracketing option, great for editing later on in workflow.
Taking picture is less then 1 minute, problem in areas with movement.
This option need some computer/editing skills.
Battery life ~2000-3000 singel shots per battery (4-12-20-28-39 for a sphere, depending on bracketing), with a spare battery you will never be without power.
Everything is fixable in editing if you use atleast 3 levels of bracketing, 5 levels (240MB/sphere) is optimum for speed and quality.
With 9 levels of bracketing you can make a scrapyard look like paradise, or fill a HD very fast…
Time differanse using 0 or 9 levels of bracketing, less then 30 sec per photo, in your case it’s 600 minutes.
3TB required for the project before edit. 12GB in a 36MP/10MB resolution/compression solution.
I would offer them the DSLR solution, with the IRIS as a low budget option.
As it sounds like a lovely resort.
The one snap cameras have one thing in commen, not the best dynamic range.
This usualy will show if you try to capture great distant views with them, here they usually fall short.
I have seen 2000m high mountains look liking like a horizon, haze just white them out.
This doesn’t allow you to take all pictures at once.
With a one snap camera, I normally take first photo after sun just gone down, then it goes fast untill light is to dark.
This is where the bracketing of the DSLR comes in to play, it can be used all day long.
Another option is to team up with an already equiped and skilled DSLR photographer and do the job together.
You get training and experiense, don’t have to pay for the equipment or education.
Might earn less, but get more in the pocket in the end.
Not to mention a lot wiser for your next project.