07 catalyst vs 07 voodoo vs F3

[baseballmom]

I think I have narrowed my choice down to these 3 bats for my 11-year-old (4' 7", 80 lbs). He is currently using a 31", 19 oz liquid metal but his coach said it was too long for him. He used another kid's 30" big barrel and now he wants one. He used another kid's stealth and hated the way it flexed. I don't want to spend more than $150 which is why I am looking at the 2007 models. He is one of the better hitters on his team - no homers yet but has no trouble putting them in the outfield. We had decided on the 07 voodoo because it is only $80.00 at justbats.com so it seems like the best bat for the money but when I called them to order it, the guy told me he thought it was a bad idea to go from a -12 to a -7.5. I continued looking and found an 07 catalyst -10 for $150, but when I read about the F3, that sounded like the best bat to buy. I personally like the techzilla but my son is insisting on a big barrel, so that is out. The F3 is also hard to find in a big barrel. I need advice before I make this purchase. Here are my questions-

1. Is going from a -12 to a -7.5 too much of a change?
2. Are blemished bats truly ok to buy?
3. What is the most important technology to look for - double wall inside, 100% composite, 1/2 & 1/2 composite, etc.
4. Which is the best big barrel bat that I can get for under $150?

Any input is greatly appreciated. His first fall game is next Saturday, 9/8, and I was hoping to have it by then. Thank you!

[Mid-Ohio Blaze]

at justbats.com you can narrow your search for just bigbarrel bats. Here is the link.
http://www.justbats.com/products/listview.asp?g=40

My son has both the stealth and the vexxom big barrel bats. Both are good, he likes the sound of the easton better. We just bought a combat b1 small barrel and it outperforms his big barrels. However we are waiting for a composite big barrel that is at least a -12 drop. I am not sure if that is possible but we are crossing our fingers. You can get a catalyst -10 big barrel in your price range. They are the blue bats with yellow writing.