RE: The right Li-po?
I use the Kokam 11.1v 1500 with an e-flite 400 (which i think is the equivalent of the Himax 2025-4100), CC 25 ESC, and a GWS 9070 prop at 6.6 ratio in a GWS Spitfire. Flies great here in Colorado at 6000ft. I don't have a Wattmeter, so I don't know the amp draw, but motor and battery come in only slightly warm after 10-15 minutes of 2/3 throttle flights. I thought about using a 1200 or 1300 battery, but found the 1500 on sale. I needed to enlarge the battery compartment a bit prior to joining the fuselage halves, but it fits nice and snug.