Well, it really depends what you want to do with the plane! I'm building a WM T-34 too, but I'm putting an Irvine 53 in it, which I know will over power it, but I'm also using a three bladed, larger prop for better scale looks, so that extra power will come in handy. As far as flying goes, are you looking to just do laps in the landing pattern, or are you looking to get a little crazy with it? If you want the extra power, I guess I'd say for for the G51, but I would bet that the Evo isn't far behind in power, and as far as value goes, my first engine was the Evo trainer power system, which is basically a 46, and this engine is awesome. So easy, no fuss, and even after I lost my first plane due to an unfortunate trainer incident, which resulted in the plane impacting the runway nose down, nose first (ouch) once I found the little Evo, cleaned it up and replaced the broken remote needle valve bracket, it still runs great and I have it on my new Kyosho Calmato. So, my sentimental favorite would be the Evo, especially since these little T-34's are pretty small and that 46NT will give it plenty of pull...a lot of people are using OS 46FX's on these planes, and say that it's all you need, and the Evo 46NT will be a very close match to the OS, at a much better price. That's my two cents...