If you're planning on buying it anyway, and don't plan on waiting in line at the Apple store the day it comes out, maybe you'd like to buy it at Amazon and throw us a referral? They've set up a special landing page for you to get all the details - right over here (The W at Amazon).
Keep in mind this'll only work on Intels - if you have a PowerPC, you're stuck at 10.5 (and probably need to think about upgrading some time in the next 24 months).
For editing, I recommend Audacity. We train beginners using this program, but you can do some advanced stuff as well. It's pretty straight forward. http://audacity.sourceforge.net/ What you are wanting to do, however, isn't an exact science.