OS3.9 will work well enough on that setup, especially if you don't use a JPG for your WBPattern. It also makes it easy to get online since it comes with Genesis.
3.1 would be quicker, but after using 3.9 for internet stuff I wouldn't look back, myself.
IBrowse is the most capable browser for that setup, in my opinion, unfortunately only the demo (30 minutes at a time) can be obtained legally. I'd still pick it over AWeb (which is free, as far as I've seen,) though.