Ive just fitted one to my xe and i think it handles better with it fitted. It is the thicker 22mm one with polybushes.
Lots of models had rear arb's fitted but the GTE/GSi one is thicker. I think the later SRi's and TD's might have had the thicker one as well.
If you do fit a front one on your LET you will need lowering blocks otherwise it hits the exhaust manifold, i got some off the bay.