BlackBerry Theme Builder 7.1 supports most of the OS 7 devices out there, which include models; 9981, 9930/9900, 9860/9850, 9810, 9790, 9380, 9360/9350, 9320/9220, and 9310. You can also export the theme(s) for OS 7.0 or OS 7.1 compatibility.
RIM has since removed most of the links.
Alternative ones here
SendSpace:
Download BlackBerry_Theme_Studio_v7_1.exe from Sendspace.com - send big files the easy way
Ge.tt:
BlackBerry_Theme_Studio_v7_1.exe