I second the 1100 NiMHs. Great choice when it's a little breezy and/or using 11x8/12x6 props. Just be careful using full throttle all the time with this set up on your 5A ESC - you may want to bench test the current draw if someone hasn't posted this already.

Another choice is an 8x720 NiMH pack for a 10x4.7 set up - it draws less current, flies slow enough for beginners, doesn't need too much retrimming when changing throttle level a lot, light enough to get a 13oz AUW and really float this baby in a slight breeze.