yeah the one600 can be fun sometimes, but i'd go for an sx-70 if you want to continue using 600 film. you can do a simple mod like i did (just remove the dark plastic in front of the meter and turn the dial all the way to dark) and get great photos, and you get the beautiful dof of the sx-70. or you can use an ND filter, which is the most popular method (but i prefer my way). someone will probably mention an electronically modified sx-70, but really why bother when you can buy an original for $45US and do the free mod yourself.
if you want to use packfilm, then you can use anything from a $3 colorpack to a $300 195 to a $600 600SE, and all are acceptable in their own ways. in fact, the cheap hardcases rarely give bad exposures... i love my colorpack III and big swinger 3000. lots of options in the packfilm arena.
you can browse thu my flickr stream to see the output of different pola cameras.