In the end... i think my question has been answered. Thanks Ivan.
Although i'm now leaning towards the 20 gig, I'm pretty sure i can upgrade the the cheap one and install a hard drive afterwards if i want to, so i may just get that one and save some cash for now.
(and yes... Benzo the PS3 is very tempting. just don't think i can spend $400 on the system. i'd rather spend $279).