This is not going to be cheap !!!

As a "GENERAL RULE OF THUMB" figure 100 watts of electric power per pound for general sport flying (mild aerobatics ) The AXI 4013-16 (or the EQUIVALENT) would be a good start for a motor. Figure at least a 6 cell lipo and a minimum of a 70 amp ESC PLUS a ubec (ultimate battery elimination circuit).

You will need a charger designed for lipo batteries. Charging a lipo with a regular charger will most likely not only ruin the battery, but could easily start a fire or cause the battery to explode. If you already have a GOOD charger (one that will handle 8 - 10 cells nimh), SLK sells a "LIPO converter" that will safely allow you to charge lipos from a regular charger (I have one and use it with an Astroflite 110D ).

For 40 size planes I run a TowerPro 3520-6 or TowerPro 3520-7 motor, 60 amp ESC, ubec, a 4 cell 4,000 - 5,000 mah lipo and a 12x8 - 12x10 e-prop. I normally get 15 - 20 minutes of mixed sport flying (mild aerobatics) and equal performance to a 40 - 46 2 stroke engine.

You should also D/L MotoCalc. It is a free D/L that can be used for 30 days before you have to register it (after 30 days it quits working).

You will see with MotoCalc that gearing and/or prop dia/pitch can radically impact the performance of a given motor/battery setup.