You can also make the song in ( or with ) the PA80 and then later assign the guitar part to a dedicated external sampler ( or a computer based software sampler ) via midi. I wouldn't be put off totally on any board for studio / home use strictly because of a few sounds, or the lack of sampling capabilities if it isn't a dedicated sampling machine.

Workstations, and arrangers in particular are manufactured more or less as all in one boards. Yes, some of them allow for sampling, and the sampling functions can be useful on them, but I have yet to see the arranger or workstation that has sampling capabilities that will match up to a good quality dedicated sampler, hardware OR software.