Check out ltsp.org
I believe that may be your solution. I use it at home (5 thinclients w/o hardrives booting from a "server", a PIII, 512 MB in the hall closet) and have excellant results. Too, my employer recently began using it (25 thin clients) and is in love with LTSP (as is the company CPA!).
Pretty much painless as long as you read the install instructions first
. I do believe there may be support for wireless, too. Not sure , though.
Hope this helps.