As above, only some have the thermostat issues, mine never did.
The clutch is piss easy to replace yourself, so you won't have to worry about rip off garages. Even easier if you have an air2air intercooler system in place, because the biggest ball ache is moving all the hoses etc out of the way before even starting on the gearbox. Otherwise, a decent AP clutch will set you back a couple of hundred quid and that's it.
They are probably the most relaible of performance cars on the road, very limited few that are unreliable, mostly down to previous knobbers who have gone on to do bodge jobs on them.