definitely go with the 808d1 batteries. DSE stuff has turned into real crap. I've had 801 batteries die one right after another.. sometimes as quickly as a week. The 901 batteries are better, but they get loose connections and are worthless when they get e-liquid in them.
a manual 808D battery and you're good to go.
i use RN 4075 atties and have yet to kill one. they work with any 901 compatible equipment. I don't know who in the US sells them, but i get mine here:
nice beefy bridge. no washers or other crap in them
Spare parts - Wholesale & Retail Best E-smoking Supplier
air mail shipping is about $3 for small parts orders and takes about 3 wks.