DuoX2 Cromwell Edition
 

Any Reliable sites left on purchasing this chip..I desperately need of one for a friend on his xbox..

Hmm, well, I have no experience with many of these shops, but here is a list of places on the duo modchip website:
http://www.duomodchip.com/english/links.htm

The very first one, DiviNeo, is the only place I heard of and seems to be a popular chip shop.