For your purposes, the Traxxas batteries would be fine - but for a few dollars more, Duratrax makes a battery that offers 50% more capacity and a hard case. Hard case batteries withstand abuse far better than their soft-cased counterparts, and are generally safer to use.
http://www3.towerhobbies.com/cgi-bin...?&I=LXBDBH&P=0
Personally, the universal connector used on the Venom batteries are enough of a deterrent - lose the adapter, and you won't be able to use the battery... Regarding cell quality, all 3 offer cells that should provide a decent lifespan, and offer decent runtime. However, if you start considering an upgrade to the motor and ESC, you'll need better batteries.