Now the journey begins......this is a road many have traveled. And many here are still traveling.
I use the the D70s and it is a great camera. Others use the Canon 20D. Either camera will be a good choice. Just decide if you want to buy Nikon or Canon.
I think the Sigma 8mm would be the best lens to choose .
You could go the Coolpix route but as you become more experienced you will just be wishing you had a DSLR.
With a DSLR you can take high quality images that will make very good panos. If you have non real easte customer that wants some full screen panos or need some stills to go with the pano then you are ready to go.
For the cheaper real estate panos you can make panos just as fast and much better than the competition using the one shot lens stuff and the FC-E9 users.
Pretty soon you will be wanting a Mark II like the rest of us....LOL
I have bothe a D70s+Nikkor 10.5 and a Coolpix 5000+FC-E8. The Coolpix is a great little camera and makes great panos. BUT I hardly ever use the Coolpix because my D70 can do ANYTHING I need it to do. Once you become familiar with your camera and learn a little about photograpy....meaning exposure,bracketing, HDR, and so forth you will find that a DSLR is just a much more powerful tool.
I would not recommend the Nikor 10.5 as a beginner lens. It is a very good lens but requires a little more skill to shoot with and it is more time consuming in post production.
In realeaste tours time is money and you will need to shoot in a timely mannor and have limited post processing if you want to make any money.