Here is a list of T-mobile phones with 3G and UMA
http://www.cellphonesignal.com/t-mobile-phones-accessories/2700-list-t-mobile-s-3g-uma-phones-phone-directory.html
Right now T-mobile don't have any phones slated for release with bot UMA and 3G.
Oh, and 3G will be out by the end of summer, 2008.