Here is the AXI 2826/12 motor I own
http://www3.towerhobbies.com/cgi-bin...?&I=LXPPX7&P=0
Designed for models up to 3.3 - 6.6lb (1500 - 3000g)

Here is another link for the motor I have
http://www.hobby-lobby.com/brushless-axi2826.htm

Stated: More powerful motor replacement for .40 and .46 size glow powered airplanes.
Sells as combo with 40amp ESC

The Mark II is a .25-.40 size kit, flying weight around 5 lbs, so according to these sites the motor is more than enough.

Thank you all for your advice, greatly appreciated. I am doing my homework.