I have created a centaur and centauress using P4 horse and V2 & M2 for the human parts. It is a bit of work but looks good. How busy do you want to be setting it up? :) The only other one I know of would be the DAZ MilCentaur which was a merged mesh set from M3 and New MilHorse. But they went into a production coma when they supposedly hit the wall with technical problems and haven't done anything more about it.