I'd go with a 11.1V LiPo 2000-5000mAH

Any hobby shop shop be able to hook you up.

All you will need is a LiPo charger with balancer.

So many options out there it's hard to recommend any one brand.

I'm also interested in what would be good for me. I have the ez complete coming but I plan on getting at least 4 more servos (I may even get the HD ones) over the course of the next few months and probably an h-bridge or two. I also know that buying batteries is already getting to be like a grocery so I definitely want to go to a re-chargeable power supply.

I have found my perfect battery, there are several versions: 7.4 v, v 11.1, v 14.8, etc ... 10000MAH case of autonomy will have long lead times. For my ideal is 7.4 or 11.1 v. Weight is lower than can be found for 10000MAH, and its price is very succulent.

Lipo 7,4V 10Amp

Lipo 11,1V 10Amp

i am thinking of using lipo batteries but they seem a bit high maintnace? like having to buy a fire proof bag to charge them in and having to dis-charge them ect. i just want a good robust battery. has anyone had any problems with lipo batteries?

I can suggest Ni-mh rechargeable battery packs because you can charge them at any time half full or dead. plus you can always guest put Ni-mh rechargeable AA batteries in the supplied pack.

I use LI-ion cell phone batteries that already have the (PCB) Power Control Boards installed on each cell. You can buy them in bulk from many online stores. They are available in many different capacities from 700 to 1600 mAH. Each cell pone battery is either 3.6 or 3.7 vdc and can be connected in series and parallel arrangements to obtain the voltage and capacity required for your robot project. What's nice is that you can use stock NiMH, NiCD chargers to charge these cells. No special protection or charger is required. These LI-ion cells are also lower in weight and generate no heat during charge or discharge.