I just got an E12, and really like it. I used a leftover pocket clip from a AA mini maglite. A little snug, and the part that slips around the body of the light is wider than the notch, but it seems to work OK. I use the clip more as an anti-roll device than a pocket clip.
This what I use for 5AH SLA's:
http://www.allelectronics.com/make-a-store/item/BC-212/12VDC-500MA-2-STAGE-CHARGER-FOR-LEAD-ACID-BATTERIES/1.html
All Electronics also sell a 1 Amp version, but for 5AH I think the 500mA would be better. It doesn't say it charges AGM batteries, but one of the...
I just ordered two of these from Amazon. $18 each shipping included.
http://www.amazon.com/dp/B004B9ZK4M/?tag=cpf0b6-20
Fulfilled by M Z Photo, who I've never heard of. This is the Australia/New Zealand version with slanted prongs on the plug. Doesn't include a DC cord, but it's a fairly...