Which motor (E-flite)?
 

Power 60, 60B or 90 motor?
I'm putting together a Cessna ARF. It will weigh approx 12lbs.
I'm planning on using two 3s 4000 mah packs in series and a 100 amp Pheonix edge 100 ESC and a 15/8 or 16/8 prop
Top flite recommends the Rimfire 1.20 motor, but I have the E-flites on other planes and haven't had any issues so sticking with what I know.
Which motor is the best choice of the three posted earlier?

Tom

If you want 100 watts/lb or higher, any of those motors will do. The lowest wattage is from the 400 kv Power 60 @ 1200W = 100 W/lb. They're all good for 6s. It will come down to your prop choice. To ensure some wiggle room, you may just want to consider the 470 kv Power 60 or the Power 90.