There are entire romsets around based on mame037b5. I can’t tell you where to look (forum rules), but these work really well with the RetroPie’s mame4all emulator, as it is version 0.37b5.
The emulators included with RetroPie are rather old. The thing is, newer emulators may be able to play more games but they tend to be a lot slower. This is because the developers are going for perfect emulation rather than fast emulation. If you want the widest selection of games, you need to look at a PC. But the Retropie can play several thousand, so you should still be spoiled for choice.