Hi Clive,
A lot of info on the e30 3series can be found on
www.bmwe30.net (or
http://forums.bmwe30.net/).
As my dad had the same car as you are telling about (he only had a manual gearbox), I can tell you the following.
The engine is good, the 6 cyl will probably last pretty long, 122k (miles or km?) will last for longer (longer if it's in km

).
You have to look for rust, that can really be a problem (the body is very prone to rust), so be sure to check that well.
The e30 is also very popular with young ppl, so try to get some history on the car, as it might not be handled very well.
Let me know how it goes!
- Ilir