My plan is to buy an older G4 model and upgrade it. I'm looking at the old Sawtooth, Gigabit/Ethernet, Digital Audio, and Quicksilver models. I'm wondering if the small increase in price for the DA and Quicksilver models is worth the 33MHz more of System Bus. I'm going to be doing mainly gaming, so would I see a difference in a 100MHz Bus vs. 133MHz Bus? Also, does anyone have any suggestions as to what model I should buy? I plan on upgrading with an OWC Mercury Extreme 1.5 GHz chip. Thanks!