For how Camsoft works and ease of set up read this thread:
Camsoft will have no more trouble doing five axis simultaneous machining than it does with my four axis mill. This is because of the dedicated Galil motion control card (galilmc.com) that provides the real time motion control. I see Camsoft now offers a less expensive motion card, but I can't comment on it's capabilties.
The difficulty will lie with a CAM package to program your machine, unless you're doing all manual Gcoding. Making the POST from this package work seamlessly with Camsoft will take some effort.