Hi folks,
Can anyone recommend me a waterproof suit to go over leathers…
Cheers 
hein gericke 2 piece, cheapish, never let me down yet and fold up nice and small under the seat.
They do a 1 piece too but you will find it pretty interesting putting that on without falling on your arse:)
Spada (from Inifinity) are cheap and effective. They do one or two piece.
I tend to use fabric when touring, and can go throught pretty heavy rain without getting soaked due to the fairing on my bike, but I have a Hein Gerricke one piece that has proved itself on many occassions in the past , personally I find it easier to get into and out of the 1 piece compared to the 2 piece, don’t forget the shopping bag for getting your boot through the leg 
I’ve got an Alpinestars El Nino suit - kept me dry in a few long heavy downpours, well made and has combat trouser style pockets too.
I have a 1 piece waterproof oversuit, I think it is Buffalo, but not sure. Does what it’s supposed to when it rains, but is a nightmare to get on. The cuffs are elasticated and don’t fit over my winter gloves and if I put the suit on first, then I can’t get my gloves on. Also being waterproof, it has no stretch so I have to contort my body in a number of ways to try and get the thing on.
So I am now looking at getting a 2 piece suit. So I can’t really recommend a 1 piece, but having said that I have no experience of a 2 piece…