From your description, OEM exedy replacement ~$180 and machined flywheel $50. Lightened flywheel means it will rev faster but also lose revs/momentum faster so it works both ways...which means it can take longer for the clutch to grab if you tend to slip it.
I take my car to the track (when I have $$!!) and stock clutch/flywheel is fine, in fact I want it to be my weakest link and not the gearbox on a mid-engined car :)
Unless you're heel-toeing almost every corner you won't realise the benefits of lightened flywheel as much imo.
My 2c :)