I could check out rocket arena at some point, I never played it before but it will be quite some time still before I would transition or make a server for it. Mostly, I need to spend the majority of my ut time improving/working on the London combo server since that is where the players are; it is the priority.
There is a RocketX IIRC server in the US that gets or used to regularly get 8-10 players in the evenings EST time, is that a different game type than you are suggesting? There is also a lowgrav RA server in the US. Are you suggesting lowgrav RA or just normal gravity RA?
Current new servers in the works are: a Face only London server (actually just got it finalized and put up yesterday have yet to announce it) and a sniper arena server in new york. The sniper arena server may eventually be moved to London also but I thought it might be best to try it in the US first where it used to have some popularity long ago. It will still be some time yet before the sniper arena server is ready also.