We've been in the bdsm/fetish niche for over a decade, producing our own original content and operating several financially successful paysites.
Sounds like you've cleared the first major hurdle - investing in your gear, models and having your content.
The next obstacle is marketing it and gathering momentum. And that'll take a lot of time and effort. Getting together with a knowledgeable and experienced partner is a fast-track, but can easily lead to problems and frustrations farther down the road if/when a power struggle takes place. My advice is be VERY careful who you choose to partner up with if you decide to go this route. There are a lot of not-so-ethical people out there more than willing to take you for a ride and unfairly capitalize on your hard work.
Take some time and learn how to build your own paysite and get some affordable hosting (we currently use
www.canaca.ca and have found them to be excellent and reasonably priced).
Check out Verotel or CCBill for processing.
Get some reciprocal links going with as many other quality fetish-oriented websites as you can. Get involved in TGP promotions. Join forums that cater to bdsm/fetish photographers and webmasters and make contacts. Consider attending and exhibiting your work at conventions such as FetishCon (Florida) or Bondcon (Vegas). Market yourself with the same enthusiasm you have when shooting the content. Work on building a respectable search engine ranking. Develop a unique style or brand for your work - try and come up with an angle no one else has already done a thousand times.
Its all in the momentum. It ain't gonna happen overnight, though. Aside from the monetary investment, it'll take time, diligence and perseverence.
And as the chorus says - post some samples.