@kjk200:
You order only bodies - which drop-in will be built in?
For example: The XM-L is a good flooder (big spot, but not extrem distance). Other drop-Ins are better for distance but have smaller spots (for example the R2 Drop-Ins).
What do you prefer?
Do you want to use only 18650 (=3,7 Volt) or 2 CR123 (=6 Volt), too? Only 18650 would be better, because many drop-ins work fine with max. 4,2 Volt.
For 6 Volt you have to search.
What's mAh:
Short words: More mAh, longer runtime of the flashlight.
But don't buy cheap crap like 3600mAh or 4000mAh - that's fake mAh - they are much less.
Take a look at the battery data base of the forum:
The flame trustfire are good or the Hi-Max of ebay - both have a good Price/Quality.
You are a beginner - please take protected batteries. They are saver.
Your DX charger:
I do not have any information about it (have never seen a test of it).
You wrote: Deal Extreme. It's a good shop, but often shipping takes a long time (for about 4 weeks), Manafont is faster (I think most users of the forum get the items after 2-3 weeks).
I post the products of DX and if Manafont (they have a better charger, which DX not offer):
18650:
DX
Manafont
Charger:
Manafont
Cheap and good one, if you want to charger with USB:
This one work also ok (a friend use it) - it's cheap and everything work. I do not trust the product 100%, but since March it is in use.
http://www.manafont.com/product_info.php/ac-lithium-battery-charger-for-18650-100v240v-p-5641
Some of DX:
http://www.dealextreme.com/p/18650-digital-battery-charger-3499?r=28318244
Hope this would hlep you a little bit.