Get one with the cambelt done.
I have a 2002 172 and it needs engine mounts, wishbone bushes, top mounts, will it did, I have just done them. So budget for them if they haven't been done or if it done low mileage.
It still needs the exhaust looking at is it knocks too.
Check the air con clutch engages when you turn it on.
Check the synchros are slick too.
Check the steering wheel condition.
Check the electic windows work. The auto xenons and wipers.