The Ej22T is substantially heavier than a number of other EJ series engines because it's closed deck. An Ej25 may be a better starting point.
Unless you are planning on rebuilding the engine yourself, I suggest you contact Colorado Component Rebuilders. All they do are Subaru engines. 2/3 or more of their business if for the homemade airplane and helicopter market. They are experts on what you are doing.
At $800 that Ej22T powered car is well price and you can make some money on that engine. It is a very desireable engine for other applications and you can help fund your project if you have the time and ability to part out that car.