My 2cents...order some cartos to give it a try, you wont be disappointed, they are much more reasonably priced, and you could always go back to the tanks. I will look for a good carto match & deal for you and post again.
NEW Soft Tip GP510 Cartomizers for 510 or eGo $4.99 !! (and there's a 5% code) 2.6-2.8ohm
Empty GP510 Cartomizers for 510 or eGo 2.5 ohm
A variety of blank (empty) cartomizers for Vapor King and other KR808D-1 style E-Cigs 2.5 Vapor4Life.com Anniversary Sale 27% off on everything this weekend. No Minimum. Coupon Code: ANNIVERSARY27
Lower Ohms are available and workable on the Ego batt as its 3.2v under load, but it also depends on your preferences and juices...if you want good vapor and great flavor all of the above would be good and less worries about burning and gunking your cartos. I love my Bloogs best...even on my Ego batt, but you would need an adapter as they are 808 threads (although an adapter is only $1 from goodprophets)
DONT GIVE UP!! I would offer to dig up something to send you to get by, but you could have an order in from a vendor sooner than you could get it from me up here.