~300gb single platter PATA hard.

[semo]

or maybe a SATA version with a decent pci (parallel) sata controller

also, what's the best way to find out how many platters an hdd has? manufacturers and reviews rarely mention it

 

[mpilchfamily]

They don't mention it because it doesn't really matter much how many platters there are. Read speeds may be better but then a review tells you which drive operate faster. . Plus reviewers are not going to test a drive then open it up. Its not one of those items you can open it up to see what it has and then close it again and expect it to work after that.