Looks like the head gasket on my MY99 WRX is leaking. The clutch is also knocking on heaven's door. I've decided to get both the head gasket and clutch replaced at the same time. Whilst the motor is out I'll be rectifying a few other issues (cv/rack boots, shifter knuckle).

By way of background I bought the car as a toy/project. The whole point of the exercise was to own a tidy near-stock classic that I could modify over time to suit my taste and take for the occasional squirt at a track. There's 160,XXX on the chassis and motor. Apart from the mechanical issues it's in pretty good nick. It is not a daily driver.

That being said, while the motor is out are there any cheap/worthwhile mods/upgrades I should do to improve the longevity of the motor and, in a sense, future proof for very occasional track work? I'm hoping to take advantage of the labour cost involved in the HG/clutch jobs.

Can anyone recommend a clutch? Would the Exedy OEM replacement suffice?