Difference in Kyosho and RCP might be track height.
If you mix the two, my experience is that it gets bumpy.
And bumpy is not good
For RCP there has also been differences from some years, but mostly on direction on the cutting.
In my little experience, 30cm tiles have more often variation in track height than 50cm tiles, but it can al be down to age of the pieces. If you get the whole track at once it might be better....

This is just MY personal opinion:
EVO version is no faster than MR03. Still same FET's. Same chassi.
EVO has no better steering if you use old transmitter. But is much more precise with the new high end transmitters.
But EVO is newer and you might get original parts easier. Like the motherboard.
I would go EVO if I did not have 6 other Mini-Z chassis and a transmitter already. Front end and rear end I could still use my optional parts.
But with that said, no need to get the best if there is no club near by. If you drive at home with yourself. You can get whatever you can get. A used GT Modified and swap motor for a 70T / 3500kv motor is probably the best. And if you and a buddy drives sometimes, it's better you go together and decides what to do. Much more fun driving equal cars.

Personally I like PN Rules, since they are doing really world cups and drivers from all over the world is joining.
Where all drive on the same surface and competing during a weekend.
Those rules are based on years of experience and with input from the drivers. Of course it's PN, so you can go all out except in 1 or 2 of the classes.