For trainer I recommend:
Avistar
Really I think any of the trainers you mentioned will be fine. This one is only 99 bucks! Not bad.

For an engine:
TT BB .46 PRO
The O.S. 46FX I think is a great engine that will work in most any plane with great power and reliability. That being said, The TT .46 PRO is a great engine for the price. A BB engine with good power for $76 is a great deal. Especially if price is at all an issue.

For a radio:
This was a dilemma for me when I was starting out. I wasn't sure if I was going to stay in the hobby and get additional planes or not. So I went with a standard Hitec 4 channel radio. Then On my next plane I bought a World models p-51 with retracts. I needed a 5th channel. So I had to fly around with a nice warbird with the gear down the whole time. So now I had to RE-invest in another radio. Fortunately I got a deal on a Futaba 6XAS. Got it, the avistar I mentioned, and a supertiger gs40 all for $250. WOW!!! So I made out but I wished I had got the 6 channel to start with. So with THAT being said,

Futaba basic 6 channel

This is what I would go with if I had to start all over again.

Just my $.02