Why not go silent with an SSD? There are SATA/SCSI converters. Drives are cheap, but the adapters can be pricey.
PFS3 is about the best option out there, 3.9 is fine, although you could try some of the light variants out there if you don't mind losing eyecandy... Used betterwb for abit, pretty snappy...
Saw you were going with the PIV, these are the best Zorro Video card. I have never had or tried one, but wish I had one...
