Right,
Top End
Get a copper gasket much less chance of warping
Head off, skimmed and flowed.
Cams, check for wear on them and will probably need replacing.
New Tappets, Valves and valve springs will need changing both exhaust and intake.
Pistons will need replacing regardless as they will have worn, get a .5mm overbore don't bother with a .25.
Have them polished aswell, basically so it gives a smooth movement for them during the engine turning.
Bottom End:
Big Ends (or Shells) take out and replace whilst there check the crank, this will have worn but if its only aboit .5mm then it should be ok, i personally would replace it.
Whilst in there and the sump is out, pull out the oil lines and clean them out, might also be worth replacing the oil pump.
What tinman has said is all well and good but him and everyone else seems to have forgotten one massive point. YOU CANNOT DRIVE IT LIKE YOU STOLE IT FOR ABOUT 1200 MILES AFTER THE REBUILD!!
You will need to bed the entire lot back in again, do not exceed 2.5k for the first 500-600 miles and this cannot be covered in long runs, it need varied runs, to get up to temp and then cool down, not all in one go. after that then vary the rev range up to about 4.5k no more until you pass the 1000mile point. This will ensure the parts have settled and will not warp and cause more problems.
Agreed your car will be more responsive but i wouldn't put your hopes on massive power gains, or torque gains either, the 16v is a great peice of machinery anyhow, but expecting massive results is foolish, ideally once rebuilt it will return about 140bhp and 120lb/ft which to be fair is a great amount. Especially from such a basic engine.
Good luck with it and i hope we haven't put you off.
