Best MAME ROMset to use with latest version of Retroarch for PS Vita

What’s the best ROMset to use with the Vita? It used to be 0.78, is that still the case? Most games I’m interested in work well enough but there is one in particular I like playing on my PC but it just won’t run on the Vita. It is World Rally and whenever it starts it just displays a Co Processor Not Present error, but the same ROM works on the PC so I’m guessing it’s either the ROMset, the Retroarch MAME core or a combination. Any tips? Also, should I be using the Piglet version or standard?

Thanks in advance.