All of the above is good advice.
The turbos tend to have engine oil leaks, the n/a versions can have gearbox oil leaks, but not generally the other way round! My n/a has never used any engine oil so that's a bit of a myth, at least on the non turbos - it likes Selinia Racing by the way, and well worth the little extra over Selinia 20k.
Always go for service history over low mileage - you won't find many with "low" mileage anyway depending on your definition. A good non turbo will be as quick as a badly treated turbo, and there's potentially less to go wrong in everyday use.
Cambelts must be done every 5 years without fail, anyone who says it hasn't had one because it hasn't done the mileage isn't the seller you want! Watch the temp on the testdrive too - they don't run hot unless there's a problem (headgasket usually), even in traffic.
Remember many have been thrashed & crashed so you want one with good service history and long periods of ownership ideally. Check the oil pressure is ok, my non-turbo never drops under 3 bar even in traffic and that's what a properly looked after engine will be showing.
They are great fun and not in the least fragile if properly looked after. Mine was an every day car for 7 years and never missed a beat (frozen handbrake aside, and don't bother trying to drive them in snow either!). The electrics should be ok too if it's been looked after.
Gavin