you need to know the flywheel clutch size, being an '89 erst engine i'm suspecting series two which has a 220mm clutch plate.
so i'd get an LUK FRST clutch kit, should be good for 180-190bhp, i had one on my xr2 zvh, now on a paddle as it started to slip when i turned boost up a bit too much for it to handle.
LUK FRST clutch should set you back around £70 from a motorfactors.