Couple of things for you.
Will a proper functioning slave, the clutch should be nice and light, no rough spots in its travel and should engage fairly close to the floor. If it is slipping it is done. Doing a clutch is no big deal, just build the cost into your purchase offer.
For wheels, the original rear wheel/tire was 18x11 with a 295/30/18. When folks move up to 19 inch (notice I did not say upgrade
) the tire is a 295/30/19 which is a full inch taller in diameter. They fit fine, but are taller, make the gearing taller and, to me, look odd... Sort of like 18's on a G series 911...
I am not sure what to make of your pic in your other thread with the coolant leak. The shop could have easily pressurized the coolant system (through the tank) and easily identified the source of the leak... Coolant should be pink...