@ Codehunter
You'll need 3.1 Kickstart Roms to upgrade your system past 3.0, but bear in mind that the latest operating systems, 3.5/3.9 require a 68020 at least, so you'll need a turboboard in that A600 to upgrade to that. OS 3.1 will run fine though, and it's worth upgrading to that, as many programs or patches, etc won't run on OS 2.0 now. You can put a larger hd in with the standard IDE controller in the A600, it's a 44 pin, so get any laptop HD and it will work fine, the problem is the filesystem. The filesystems used by Amiga OS cannot address more than 4gb, so if you want to use a larger drive, you'll need to install a filesystem that supports it. Check out
Aminet, or check with other members here, as I don't know what filesystems you'll require, I believe it's either SFS or PFS though, so check it out. :-)