The way it works is you get a motor that has the ability to carry around the weight of the plane you are going to fly with, depending on the type of flying you wish to do. So, there will be a 'wattage' rating for a weight category, basic flight, sport flight, all out 3D flight, for instance. Then, you match the three (motor, ESC, battery) to the numbers you select. It's always good to select a pair (motor/esc that will be slightly more than you need, then match the battery capacity and delivery capabilities to your motor and esc combination. That should get you pretty good performance.

Basically: The usual rule-of-thumb for "normal-sized" (read: .10 to .60-sized aircraft) model aircraft is 75 watts per pound for trainer-type handling, 100 watts per pound for aerobatics, and 150 watts per pound for 3D.

For watts: multiply voltage times current. Power = Voltage X Current 3 Cell = 11.1 volts. So, 11.1(volts) X 25(amps) = 277.5 Watts. (just an example.. do yours yourself to see what you come up with).

There is a web site that can give you all that information and you can select from there. I don't have it right at hand, but a google search for something on the order of what you are looking for (motor and ESC for instance) will eventually find what you need.

However, based on what you said, though, this sounds like a pretty good combination for you.