It doesn't matter what resistance you're using in this mod because you set the watts and the mod keeps outputting those watts no matter atty resistance.
You've got 2 batteries in this mod and at 150 watts they will be outputting about 27 amps each so you need to use 30 amp batteries. Options that come to mind are;
Orbtronic SX30, 1600 mAh $12
Sony
VTC4 2100 mAh at Illumination Supply for $8.50. These are IMO the best buy right now, but they don't have many in stock so grab them while you can.
RTD Vapor has VTC4 for $13.
Good luck with it!