RE: Newbe at 3d electric flyiing
Check out the foam profile kits that are out there (Great Planes Flatouts, Fancy Foam, etc.) Most of them have recommended power setups. Take note of the following specs, and make sure the components you buy meet or exceed those specs:
1) Battery: Number of cells, max constant current (Amps), total capacity (mAh)
2) ESC: Max constant current, max voltage, BEC current rating
3) Motor: Kv rating (get similar rating), max current or power rating, size (get similar size)
If you want to use your existing batt packs, the specs on your packs will determine the max weight of the plane you can fly. Take the nominal voltage of your pack and multiply it by the max constant current rating for your pack. That's your max power in Watts. You typically want at least 10W per oz (for planes under a pound) or 100W per pound (for larger planes, say 2lbs+)) for sport flying, and for 3D you will want up to twice that.