There is a plane called the Airmadillo from a company called Kombat. This plane had a coroplast wing and tail feathers and a aluminum square tube fuse. its a 40 size, A/E/T/R control and is very durable. Its a good stable flier and can handle the wind.

Look for used engines, I've had good luck buying 40 and 46s for $30-40 used and they all work fine.

Another way to go inexpensively is to go to a club swap meet. I bought a 40 inch trainer for $15 (Airframe, steerable trike gear and control rods hooked up) and threw in my electronics and an old 25 and it flies real stable and slow.

This way is even cheaper than building a SPAD from scratch.

Electrics are great if you have noise restictions. The batteries are good but you really need enough batteries to do three flights to really get some flying time. Else you're waiting for them to charge. Be very careful with your batteries cause you can kill one easy by just flying longer than you should or charging them wrong.

Gas is good cause you can just fill up and fly you can fly probably 50 minutes out of an hour if you have a good receiver battery

Anyway good luck