I think it is a QuickSilver tower. But i can't remember if they had the HD size limits on those towers, or maybe i am thinking of something else [software]?
Anyway, i have two 120GB drives and another two 80GB drives in my Dual 1.42 G4 [Windtunnel] tower. Bigger drives can be found pretty cheap now a days. I would do a search on Newegg.com, and see what sort of deals you can find for internal IDE drives.
good luck, ryan