The original bore size is 75mm, so you are only 1mm bigger. I run a standard head gasket with a 77mm bore and its fine, a metal one from a 6n should be fine. All it does is lower the compression ratio. I think you will want one from the engine code AEE, 1.6 8v.
If you have standard brakes, there is no need to upgrade the master cylinder to the golf gti one. I think it can increase pedal travel or something, search the forum as there is a topic on it.
Alloy radiator is good to have as the do help with cooling but more expensive and you will more than likely need a slimline fan as well. A good oil cooler and lower water temp thermostat will be a good start as it will help everything keep cool. I have never had problems with the standard one.
FMIC is always going to have a gain but how much of a gain on a supercharger i wouldn’t know. They are more expensive and you may require, depending on where you have it, have to cut bumpers/slam panel to fit it. They can be fit nice and snug out the way to make it look like a sleeper. Yoof’s one i think is built well and can’t really see much of it.
