Alkaline, as I've said multiple times before, I think the ThunderPower 2100 2-cell pack will be what you need. The ThunderPower pack is rated for 10C and has a capacity of 2100mAh. 10 times 2100 is 21000, or 21 Amps of capacity, plenty for your A-10.

You don't plug the battery into the receiver. It plugs into the battery lead on the speed control. You'll want something better than the little red "JST" connectors for 16 Amps. Deans Ultra connectors, which are what most bigger packs come with, are an excellent option.