While I have nothing against purchasing a skin and customizing it from there, I always preferred to just draw out my style (on a piece of paper or by using MSPaint) and have it custom built. It's always been fun for me to see a design I created from my head slowly turn into a reality on the web. It makes me feel like I had a very important say in how it was designed and what the final result looks like.
For example:
View attachment 63191
View attachment 63192
It's not to say that purchasing a theme is bad as it certainly is not. You'll get a well made, professional style theme that shouldn't have any issues for a great cost that you can then expand on and customize to your liking. For me, I've just always done it this way.
I didn't read through the entire thread so not sure if you found one to use yet or not, but if not, just pick the one you really like. Go with your heart!