When I replaced the PTT on my '93, I found dozens of used units for all prices, and several new units, for all prices, so look around a bit.
A PTT unit consists of the PTT plus a wiring harness, two relays and a SPDT switch. Switches are easy aftermarket, although your control unit might have one already. Relays are not hard to wire. I would expect you can find a wiring harness, as they can come with replacement PTT motors.