S/PDIF is a digital format, so you'd have to run the triggers into an A/D converter and then digital into the S/PDIF jacks. So basically you can't really do it cheaply.
I've never fully understood the S/PDIF thing. The Profire 2626 has the crazy cable with RCA, MIDI, and I think something else? Wiki says it's for sending compressed signals and whatnot, but I just never fully understood this.
Yeah I have a toneport UX2 going into the S/PDIF input on my profire 2626. I get 2 more channels of inputs with it (although they are shitty).
I have to set the clock to the toneport (confusing to some, but no big deal in terms of quality) and I'm limited to 48K if I do. Not that this matter I just roll out 44.1 all the time.