I would stongly suggest NOT putting a g45 on that plane. Its way to heavy 5.1lbs. You need to watch the wing loading on that plane close or it will be real snap happy.
I would put a moki 1.8 on the nose, but if you wanted gas, put a BME 50 or a 3w 50. these are very light for gas engines. the BME weighs about the same as the moki 2.10. The moki 2.10 weighs about 3 lbs and has more power than the g62.
you can do what you want, Its your money but I dont think you will be happy with a g-45 on that plane.
Zenoah is more for scale birds....

My 3 cents,
Shane