RE: Feasibility
I don't know specifics, but it is going to require a lot of power. I would almost say it is impractical to do it. It will cost a lot to get the runtime you want, the motor and single speed controller (you only need one. you cannot combine two with one motor) will expensive. Maybe it's just my cheap attitude, but I wouldn't even try.
But, if you are determined, the first thing I would do is find an average thrust rating for the gas engine and try to find an electric motor that provides a similar amount of thrust. Also, you will have pretty long landing gear since the prop will have to be very large. As for the batteries, you will probably want to put a couple packs in parallel since the high capacity packs tend to be very expensive.
As for trying to get the weight up, if you have extra money to spend (or already have one) you could put a camera on your plane. I wish I had weight to spare on my plane. I've been wanting a camera for a while. But, good luck and let me know if you nedd any more help. I'll try the best I can.