Theres no need for a thicker head gasket or skimming the pistons if you dont want to as if you assemble the engine using a std 1.6 cvh head gasket and the unmachined pistons this will run 8.5:1 compression ratio a little up on what is ideal but you will have the ability to run up to a maximum of 20psi.
i have this done too my own car at the moment running a 1.8 engine, k and n filter and a scorpion exhaust with a chipped ecu running 14psi and it puts out 147@wheels /180@flywheel.

there is no other mods done to the engine its just std. the cam the head , the pistons etc etc.

However my m8's on the other hand that i made has a hybrid turbo , kent cam and a big valve head running 18psi was running 195@wheels or abround 240@flywheel quite a difference.