It's pretty easy to find a800 roms if you know where to look, shoot I just googled it and came up with a few Atari specific sites that had tons of roms. I think the best one was atarimania.
you're kidding right? with only like a kabillion games on open sites not hunted down by anyone. There was a good list of them posted to here, but I won't repeat it due to the possibility that it violates rules.
speaking of rules, if atari 800 disk image links are okay to post, (which I probably agree with) where is the line where it isn't okay anymore?