There's a reason that Pro Tools is the industry standard in all studios, and you'll see when you get a copy. I'm not sure if they still offer Pro Tools Free, but it's limited to 8 mono tracks and you can't open your sessions in later versions of PT. But for PT Free, you don't need to buy a MBox or any interface, so you can learn a little on how it works.
If you buy PT LE, just make sure you have at least 512 MB of ram and a decent processor speed, like at least 1 GHz. You can do it with 800 MHz, but I'd recommend faster.
When I had Cool Edit Pro 2.0 on my old PC, the wave editor was the shiznit. But tracking in Cool Edit was a pain in the ass. If I had more than 5 tracks, the shit would always play when it was good and ready. Although my Mac PowerBook is much faster than that old PC, I've never had a problem with Pro Tools. (I got 1.5 GHz with 768 MB ram).
Plus, if you get Pro Tools, you can pretty much have it mix-ready for any studio out there, because everyone has a Pro Tools HD system nowadays.