Ultimately do both. Start with a good sounding axe and work on getting its recorded signal as real as possible, the stereo option mentioned above is good too. Also take a wet signal from an alternate source, some sort of pickup, and tinker with the sounds. You then have the option to use one or the other or mix them. I don't personally care for piezo signals through effects processors, preferring a magnetic pickup for that purpose, but certainly there are a lot of variables and your ears will be your guide.
The other option of course is to have a variety of good sounding guitars with discernable differences, 6, 12, baritone, bass, resonator, classical, and related things like cittern, bouzouki, and mandolin, etc. (Experiment with articulation techniques, slides, slurs, bends, hammer-ons, pull-offs, tapping, slapping, and gizmos like EBow and bottleneck...much can be done with the hands alone.)
Even with all the sound/tone options, start with a good axe and good original signals with good mics and pickups. For recording I prefer large and small diaphram condensor mics, leave the sm57s for live work.