I use GoldWave, which has a lot of stuff for cleaning up sounds, compressing/expanding, and all that techie stuff. It too enables you to split big files into separate tracks, either by detecting quiet bits or manually. It's not free either, but you have to start off with the demo version (which is) before you can pay for it. If v5 is like v4, it's fully functional, but with frequent "nag" messages.

Steve