i would chose the 6200 board they have "special" 32 bit ics that inhance the compability iwth 68k software and the 603 has a 4 statge excution pipeline similar to the 604s altivic for ehanced proformance. i actually have a 6320/120cd in my room its the rarest and fastest of these reliable 32bit hyper technology designs. i got os8 it crashes alot so i mainly use it for tv which in for it waorks excellernt.