Good suggestion is to grab SATA Raid.
You can put your 80 GB in first drive and rest of it can running up with you all together. like if you have 80GB, 250GB, 500GB... when plugged into RAID board, it will make computer think all this drives into one. THat is, 830GB.
If you want to use it for lag-free gaming, i recommend you Western Digital Raptor 74.4GB (running at 10,000 RPM)
The Seagate packed the best sata hdd in the market.... 750GB SATA II. ^^