I don't know about the p-51 and the zero, but I have the GWS A-10. It flys slowly, and is a bit marginal on power in stock form, but it is faster than the firebirds. I find it easy to keep in a small area, but I've been doing this for a while, other guys may not find it so easy. (I also find it flys inverted fairly well, but again, I've been doing this for a while).

If I were you, I'd find a club field to fly it at for at least the first few flights, then you can judge for yourself if you can keep it in your normal park.