Daihatsu Rocky alternator

Hello,

I have recently acquired a '92 turbo diesel Rocky from a great mate for the equivalent of 30 cases of VB. It has nearly 200 000 on the clock and is in good nick with many extras. A few years ago he was pulling into Longreach with his spotties on and his stereo blasting and apparently drained his battery doing it. The next morning he got a jump start and found the local auto electrician. The sparky said that the diode was burnt out on the alternator and fixed the problem for $400. It seems the alternator has once again given up the ghost and isn't charging. Daihatsu wants around $800 for a new alternator. or I can get a second hand one for $200. I've never owned a 4wd before, let alone a diesel.

1. Is changing an alternator on a diesel motor any different to a car?
2. Is there anything else besides the alternator that is likely to be buggered? (no coil)
3. Anyone dealt with a rocky alternator before?

Any feedback would be appreciated, thanks.