I still prefer OS X even more so having to go back to windows for awhile.  Where I got my PC was CyberpowerPC.com  Several people have now used them over in the Daz Forums and have been very pleased with the price and what they got.  Start with a base system and mod to have everything you want.  You can nickle and dime yourself into a higher price bracket though.  That being said I want to get back to OS X its just so much nicer to use.