Both those sleds are geared 23/38 stock, reverse or not.
You have 2 options as far as gearing with the reverse kit. The 8EK kit will give you stock gearing.
The part #'s you want are:
38T Hyvo reverse kits is: 8EK-W4759-10-00 REVERSE GEAR KIT
39T Hyvo reverse kits is: 8EN-W4759-00-00 REVERSE GEAR KIT
You re-use your stock top gear and your 70L chain.
When you're finished, it takes 250ml of oil.