Here's a pretty simple instrument I made of samples of my Strat, specially for a project now finished, just direct input recorded (so you supply the cab/amp/fx!).
A full octave (and more, with pitch shifting) of major power chords at three different strumming speeds: lower velocities correspond to a slow strum, middle velos to a faster strum, high velos to a quick strum and very high velos to a quick hit with no sustain.
I added pitch modulation with an operand controlled by a macro wheel so you can automate cool surf guitar dips and such. You could map it to the mod wheel or whatever, too bad you can't map it to the actual pitch bender on your MIDI controller, or aftertouch for that matter.
I left "Vel->Vol" on on all samples, might make more sense to turn it off depending on your needs.
Sounds pretty good to me, it's best suited to mellower stuff, I've got the tone knob turned to about 4 or so and pickup selector in the second position (top two singlecoils) except for the hits, which are in third position (middle pickup only, little bit brighter and noisier).
If you're new to digital guitar amping and looking for a free cab/amp plug, maybe try Boogex or Emissary.
Edit: almost forgot, I put a few little samples of finger/string noises on the note-off layer, for extra "realism" ;). Was just fooling around but it does lend a bit of something, remove the samples from the note-off layer if you don't like it.
Edit: I've added a quick example, you can hear most of the chords and strumming rates, it's part of the rhythm guitar track from a song I did with these. Shows that a little compression, some tube clarification, distortion and reverb can make these sound pretty good, eh? What I actually used (DSP in order): Renoise's bus compressor, Studio Devil's Virtual Tube Preamp (awesome piece of software), Boogex's "Picking Crunch" preset with its cab and reverb turned off (so only the amp), Renoise's cab sim with the "Boro Jazz" preset, bass and high freq attenuated, Renoise's mpReverb "Cathedral" setting with the wet set to 20%.
Note, you will need to EQ and compress these at a minimum to use them well – they're all raw direct input samples, so the (sometimes pretty bad) harmonics and such are still there. Treat them as what they are – raw input requiring some processing! Thanks, cheers.