Buy a 90 spec (big Bumper) Mk2 as the loom is different and makes engine conversions easier - you tell these apart as they have the hazard light on the steering column. Pre 90 spec one had it on the dash.
Body condition is more important than engine milage/age as engines can easily be fixed/replaced.
Look for rust around arches, sills, windscreen wiper blank, boot, fuel filler cap.
8v's are more common then the 16v by a factor of 4-1. 8v will giver better MPG - 40 ish - as it has electronic ignition. 16v uses Bosch K-jet mechanical, about 30 mpg.
16v is better
as it is faster. The torque kicks in around 4000 rpm all the way to the red line. 8v is lower down but runs out of puff.
So you want a H/J reg 16v. These also come with power steering, electric windows and a sunroof as standard.
Check for water leaks in the footwells. This is due to shrunk/no door membranes, blocked sunroof tubes, failed seal on the blower mesh cover in the scuttle panel, and failed/shrunk grommets for the accelerator/bonnet release cable.
Check all the electrical things work. Air vent blower power may be down due to the vent direction selector membrane perishing. Tell tale is bits of foam shooting out of the vents on full blower. Bit of a potch to remove but simple fix.
Dim headlights are due to them only getting 9v instead of the full 12v. Off the shelf or home made harness can be used to get brighter lights.
As said, plenty more info available if you weren't so lazy.
Jonathan.