As long as iMac600's computer is indeed the original WallStreet, there should be no problems. It may not work in the second revision, tho. Also, keep in mind that the 292MHz model runs at 83MHz, and thus requires PC100 RAM (not that PC66 is common anymore, but just so ya know). Plus, the original 12" model lacks SVideo-out and has only 2MB of VRAM, so it probably wouldn't be worth it to upgrade it any. If you've got the 13 or 14" displays, though, or the later 12" TFT types, you would have SVideo out and 4MB of VRAM.
This is another issue with these machines. Whether yours has the RAGE LT (WallStreet) or RAGE LT PRO (WallStreet II), OS X often has problems with the display. Usually just the backlight cuts out and you can get it back by fiddling with the display brightness control or sleeping/waking once or twice. Other times, graphical corruption is also present, and there's really no fixing that without restarting, zapping PRAM 100 times, and/or using some kind of voodoo magic.
However, IIRC, XPostFacto (though technically not required for 10.2) comes with patched kexts for those video chips that should provide a remedy to the situation. You'd have to visit OWC's website for details, though.