As has already been said, much depends on your business model. However, I think if cost were not a deciding factor I feel a standalone cutter and individual printer is the overall best scenario for most shops other than those mostly doing print and cut stickers/decals with no lam.
However, if you do go with a print & cut machine at first, what happens if/when you have to upgrade? If you keep your current print/cut machine you'll likely either buy a bigger/faster printer and dedicate your current print/cut to a cutter and/or you buy a good cutter for $4-6k and likely not use the cut feature on your print/cut machine. As strange as it sounds, I know a few shops who are doing one of the exact scenarios I list above. IMHO it seems like a waste, i would prefer to spend a little more up front and grow into it vs. being forced to upgrade before I was ready and then have to shell out even more cash to fix a problem that would have been cheaper to resolve up front.
Just my .02¢