Yes it can be done on your own. Heres a link to my thread with a twin turbo kit I custom built:
http://www.camaro5.com/forums/showthread.php?t=133098. Also read gretchens threads. If you are truely interested I can PM you a fully detailed parts list that cost me only $3800 in parts including trifecta tune but can cost up to mid 5k if better turbos and wastegates are used.