KS 3.1 ROM's for every classic Amiga are available at Amigakit except the A1200, so it can't be a copyright issue, and since they are for sale at Vesalia.de for €17.90 I'm pretty sure Amigakit just hasn't burned any new ones -- ask Chris Follet about it.
The current ACA 1232 is an excellent card and 98% of all programs will run very well on it. There are less than a half dozen games and 3D modeling programs that benefit from more CPU power. It will let you game, surf (Cerf) the web, word process, and desktop publish quite well.