hmmm difficult one that.
the mileage and the original alloys would have me intrested in the 8v.
the leather interior and the 16v engine would have me looking at the valver.
hard to say really. both sound like they are going to need a lot of time and money throwing at them but only after you have bought one will you really find out how much.
personally if you can wait i would look around and bide my time for a 1991 16v as the later golfs had more spec. get one with service history and no more that 5 owners at most. make sure it hasn't been bent (too much) and has mileage of around 100 - 120K. you would look to pay say £1200 upwards but will be worth it. i consider my 89 8v to be in good condition, no rust, mechanically sound, but i have spent over £2000 on her now easy but only because she has a good foundation, eg body, engine etc. (the car not the wife).
where as the wifes 90 8v has bad rot under the rear arch and other places, its had new powersteering rack, head gasket, heater matrix, gear box, power steering pump, etc etc. and is still knowwhere near mechanically sound.
if you really want one of the 2 you have seen i would go for the 8v think but only if you cant wait for a good valver.
hope this helps