Hey all.

My father is partially deaf, and cant really play his guitar anymore because he cant hear himself. He plays and sings, plugging both inputs into one amp. His rig is terribly simple, and goes like this:

Fender Acoustic --> Dean Markley in hole pickup --> Early 1980's Fender Deluxe Reverb Amp (Input 1)

Microphone --> Early 1980's Fender Deluxe Reverb Amp (Input 2)

Now I was thinking we should be able to plug an in ear monitor system or something into this, but I know nothing about them. Does anyone else have any ideas, or an inexpensive alternate way?
Ibanez SZ320
Peavey 6505+
Marshall 1960B
Dunlop Wah
Dano EQ