^^^Sorry to hijack the thread!
Over here there are several charities which help massively with the cost of sports chairs (or even provide them foc). You may find something similar where you are?
As for putting a website or something together, I currently work for the governing body of wheelchair tennis here as a national coach, so I couldn't put something up for myself. As an organisation we are looking to update our website with more information about how to get started and develop some more resources. USTA might have some stuff too, if you contact Dan James (he's your national coach) he might have some useful info or contacts for you? Like I said though, feel free to drop me an email...
I tweet - @ashtennis guru (no spaces)
I Shoot - www.flickr.com/photos/ashtennis guru/ (again no spaces! grrr)