Buy the thermostat at the parts store. Tell them you want a 180° thermostat that replaces the stock 195°, and if they tell you it'll cause probelms, buy it anyway. You need the paper outlet gasket and rubber seal.
Get a service manual, and you won't have any problems changing it. Chilton'* #28200 is a good starter manual and should cost you less than $20.
Before you change the supercharger pulley, you need to know if your fuel pressure is within spec or not, and you need a scantool. The 92-95 supercharger pulleys don't need a special puller. Napa sells a small 3-jaw puller that will work for you. For your 94, if your fuel pressure is within spec, 2.5" is the typical performance size, but you must have a scantool to see if you have any KR or not after changing it. You will also need a 3.25" or 3.5" idler pulley for the tensioner if you plan to keep the stock belt. There'* a Techinfo article on the idler pulley subject as well as changing your SC pulley. Link at the top of the page.
I've changed every pulley on my engine. The crank pulley can fight you, the idlers and tensioners are fairly easy, and the water pump pulley requires you to disconnect the torque axis motor mount, jack the engine up until the supercharger nosedrive is about 5" higher than normal, remove the torque-axis mount, and change the pulley. It'* a little PITA.