Lots of great advice from all the others above, do the reading, you'll need it. As for the Magneto, I'd suggest getting an RSST for it and start with 1.2Ω build and see how you like it, and drop to 0.8Ω if you want more. And batteries, I'd go with the Sony 18650 3.7V 2600mAh Rechargeable batteries, they're great.