I like Ba and Best but I'm not completely convinced they'd ever form a proper partnership. There were signs of one against Blackburn, but I'm not convinced. I think they can be effective upfront together simply as they both appear to be natural goalscorers but I'm just not convinced they'd ever be able to link up.
One of them ahead of Ben Arfa is probably the way forward IMO, so long as the midfield behind that is set up right.