Aha! I see. $200. is a great price. Here's what I found out... Looks like you can go to 80gig.
Got this on the FAQ section on the Fostex America site:
Compatible hard drives for VF-08
Jumper Setting of the hard drive=Master
Make
Model Name
Maxtor Fireball 3
2F030J0/1, 30GB 2F040J0/1, 40GB
Western Digital Protege
WD200EB, 300EB, 400EB
Maxtor D540X-4D**
4D020H1, 20GB 4D040H2, 40GB
4D060H3, 60GB 4D080H4, 80GB
Maxtor D540X-4K**
4K020H1, 20GB 4K040H2, 40GB
4K060H3, 60GB 4K080H4, 80GB
Fujitsu MPG series **
MPG3102AT, 10GB MPG3204AT, 20GB
MPG3409AT, 40GB
Samsung SpinPoint V40**
SV2001H, 20GB SV4002H, 40GB
SV6003H. 60GB SV8004H, 80GB
** These drives are discontinued by the manufactures.
Note: Drives in italic red letter require Version 2.10 and up.