Right now, aside from having a couple of great amps (I have powerful Fender and Behringer "Keyboard Amps"...
and a Behringer for Bass Guitar. I also use an ol' Roland GR-303 Synth Guitar/Processor, like Metheny's.
I'm looking at this new synth contraption from Roland...it sounds great with all it's inate sounds...
The GR-55 also features a USB song player that lets users play WAV files stored on the unit's USB flash memory, and song playback can be controlled with the onboard pedals. The GR-55 also functions as an audio/MIDI interface for computers, with a rear-panel USB 2.0 port for a quick and easy connection. Users can easily integrate with their favorite digital audio workstation software, recording GR-55 sounds as audio in the DAW and using the GR-55's super-fast pitch-to-MIDI capabilities to trigger MIDI sounds such as virtual synths and samplers with their guitar.
http://www.rolandconnect.com/product.php?p=gr-55