Lithium Fastpitch Softball

Fastpitch Softball Bats?

Hi ok so I am a varsity softball player for my highschool I am a sophmore. I also play in an asa league U16. I am just wondering which bat would be better for me to get the worth mayhem or the Louisville Zephyr. They are both very similar but i think i should go higher than a 20 oz bat and mayhem doesnt go higher than that but the Zephyr does. I will give links to both bats and can I please have your opinion on which bat is better or which bad should i consider getting? Thanks!

http://www.softball.com/Softball-Bats/Fastpitch-Bats/Louisville-Zephyr-Comp-12-Fastpitch-Softball-Bat/softball/lev/6/productId/4485/No/20/Ne/1200001/parentCatId/419/Nao/20/pCategoryId/401/Ns/CATEGORY_SEQ_419%7C0/N/36+1100110+34/Nty/1/categoryId/1100110/index.pro

http://www.softball.com/Softball-Bats/Fastpitch-Bats/Worth-2009-Lithium-Mayhem-Comp-12-Fastpitch-Bat/softball/lev/6/productId/6033/Ne/1200001/N/36+1100110+34/categoryId/1100110/pCategoryId/401/parentCatId/419/Ns/CATEGORY_SEQ_419%7C0/index.pro

I'm a going to be a freshman in the fall and currently play on a U14 travel team. I think you definitely need a bat that's heavier than 20 oz. I normally use a 23 oz. bat and when it's a slower pitcher, I move up to a 24 oz. I think if you're comfortable swinging it, you should go with the heaviest bat you can. If you can make good contact, the ball will go farther with a heavier bat.
This is a link for the bat I normally use: http://www.nextag.com/Easton-2008-Synergy-CNT-559007240/prices-html?nxtg=8af0a240515-0EC597B463FA1F83
Out of the two you're looking at, I'd go with the Zephyr.