> As for versions, I pick one mathcing whichever romset I have. Archive.org posted
> a full 0.151 set (and it's still up) so that's what I went for last time I
That's what I used to get myself a jumpstart on bringing my set up to date. I also grabbed their CHDs, but I totally regret wasting my time because there was still a lot of work that needed to be done to each one and it's not like many of them are even worth keeping around and playing at the moment. Maybe in a decade.
I'm happy to see that the latest version of RetroPie is using a slightly newer version of AdvanceMAME, but I really wish they would just make a concentrated effort of maintaining ROM parity with the current PC builds.