Re- the rain garment - what about the very long hooded anoraks worn by scooterists in 1970s (& still seen at rallies)? I have a waterproof poncho-type thing designed for hikers - very snug with the hood drawstring pulled tight (not padded, but has lots of room for extra layers of clothing- even smallish bag of kit!). My arms can poke out of flaps in the sides when I need to deal with Casualties.