I appreciate your problem as i had the same trouble and was looking for a 90 for about 2 months until one practically turned up on my doorstep as a friend new a friend who was selling his.I scanned Ebay for a while and found it pretty useless as they were either to far away or the seller was asking to much,i would advise you to bide your time as the right vehicle will come along and get a TDi and not a TD,oh and be prepared to spend some more money as whatever you get as it will want some work, at least a cam belt kit,ignore what the seller says if they say it has just been replaced as you don't know what's going on behind that aly cover.
Kev