Ok I own 2 of the planes that you are looking at, the Ultimate and the Cap232. Both are DA50 powered and they are handling it very well. These are airframes that can handle a gas engine which makes this statement a little lacking in knowledge. So please explain what is a real gasser and how do you determine that. I'd really like to further my education on this subject.

both the ones I own are well over 500 flights and holding up well. There are threads on RCU that covers both in detail so have a look.

I'd agree that Wildhare is a good product and very nice for the first time gas plane buyer...

I'd go right into the GP Ultimate and do not bother with the Pitts. The Pitts is a bit touchy where the Ultimate is as smooth as silk. My favorite saying for the Ultimate is that is a big puddy tat on low rates a dna big puddy tat with an attitude on high rates

Since the original question was, what do I need to look for, I'll address that.

All three planes you are looking at will be much better with a lightweight 50cc engine. I tried the Fuji 43cc on the two I own and while they flew well, a DA50 or the DL50 is the same weight and way more powerful

For servos I'd do hitec 5985's on both on all surfaces, they are overkill but they will easily make the plane do whatever you want.

For battery power, keep it lite.

All three planes do not come with gas stoppers for the fuel tank so you will need to purhcase that as well as fuel line barbs, 1/8th inch in size.

The stock control horn setup works well but replace the metal clevis's with the Dubro Safety Lock versions.

For gas engines, a good seperation must be maintained between anything related to the engine version the reciever. 12inches is common and doable for the 3 planes you are looking at.