Congrats on that haul! The 6500/300 is definitely one of the nicer consumer computers from its era, and that subwoofer does fantastically, especially as it seems you've found out about iTunes and putting a bigger hard disk in.
Much as I hate to be "that guy" who suggests this at every turn (I kind of am though) -- have you tried Internet Explorer 4 or 5? In my experience, even though not everything displays correctly, IE5 is best for PowerPC macs with 7.6 to 9.whatever because it uses the least resources, and handles things it doesn't know about the most gracefully. You can even get to a lot of lite/mobile-version web sites (such as m.twitter.com, m.facebook.com or zero.facebook.com, and m.gmail.com or the gmail HTML view) with it.
There is also Classilla for the web, which is way more modern than IE5, and I've heard great things about it from the people here who are using it on their system 9 machines. The only downside is that it's very much a modern web browser in terms of memory usage, and may require a huge VM or some more physical memory.
Much as I hate to be "that guy" who suggests this at every turn (I kind of am though) -- have you tried Internet Explorer 4 or 5? In my experience, even though not everything displays correctly, IE5 is best for PowerPC macs with 7.6 to 9.whatever because it uses the least resources, and handles things it doesn't know about the most gracefully. You can even get to a lot of lite/mobile-version web sites (such as m.twitter.com, m.facebook.com or zero.facebook.com, and m.gmail.com or the gmail HTML view) with it.
There is also Classilla for the web, which is way more modern than IE5, and I've heard great things about it from the people here who are using it on their system 9 machines. The only downside is that it's very much a modern web browser in terms of memory usage, and may require a huge VM or some more physical memory.