Live guitar rig

[outtolunch]

A guitarist friend of mine is always complaining about how bad the monitoring is in live gigs, so he has the idea of buying a system where plug his guitars, send the signal to the P.A. mixer and hear himself well, using headphones (maybe only one ear, to be able to hear the rest of the band).
He plays flamenco very well, and usually he has to play spanish acoustic and electric guitars in the same gig. The acoustic one is a Godin, with balanced output, and the electric one is sometimes a Gibson, sometimes a Stratocaster (I don't remember the Gibson model, sorry). For the electric he needs a good clean sound, and sometimes a Santana-like tone.
So the rig he is trying to design has to be something like this:

1) One clean pre for the acoustic guitar (from the balanced output).
2) One pre for the electric guitar (so it has to have instrument input?).
3) EQ for the two channels.
4) Some way to mute the guitar that he is not playing.
5) A FX unit (he has tried Digitech, Boss and Line 6, but he doesn't find any with a good distortion).
6) Output - to the P.A. mixer and to his headphones.

He can spend about 6000$.

I'm not guitarist, so I don't have much idea of what are the best options or if it is a bad idea to gig with that rig. What are your suggestions?

Thank you!