I got a OCZ 450 mod stream ( modular ) in my other system..love it!
Thermaltake is ok but read alot of threads on the problems with it the rest I have know idea about
generally i stick with good manufactures like, PC power and cooling, OCZ, seasonic, futron source, and a few Antec products. OCZ is the only one that makes modular PSU from the above list given
any of the above would be a good choice!
I have a Antec TruePower 550 watt for $89 (last month I had a 15 rebate that made it 75 ) that runs very stable. It is powering an X1800XT, 4 SATA drives in two RAIDS, an Opteron 175, and a DVD Burner with a TV Tuner card.
My TP550 has only one 120mm fan, there is an identical model also with two smaller fans like my TP430watt has, which is good too.
Then their is the TrueControl 550 which is just the TP550 with fine adjustments on the rails to tweak output.