Hi,
My workshop has corrugated sheets on the roof (asbestos substitute type - big 6 size) and I have 4 corrugated clear panels in there as well. The condensation is a real p.i.t.a. and so I've started insulating. I've fixed a 4x2 timber surround to the underside of the clear panels, and am in the process of fixing twin wall polycarbonate sheets to the timbers. This will effectively double glaze the sheets whilst hopefully not obscuring too much light. The rest of the roof will be boarded in ply or osb and the gap between roof and board will be insulated with polystyrene or rock wool, depending on what I can get that keeps the overall cost to a minimum. The workshop is 39ft long and about 18ft wide, so there's a lot of roof space to cover - it's not going to be cheap, but I'm really fed up with drips of condensation all over my tools etc. Hopefully next winter the workshop will be dry - and a lot warmer.
I have some friends who roofed their stables in a bitumen corrugated sheet, and they were really disappointed in the durability. Easy to cut and fix, bit they have had to replace them after only about 8 years, so they have chosen an alternative. I have no experience of these myself though. If you go for corrugated galvanised sheet, expect to have to insulate as they are totally awful for condensation.
K