I would favour Gerbing too as I've already got the wiring installed, a double controller and their trouser liner that works a treat. Problem is I need something for the top half too and their XXXL is their largest and doesn't fit me, and I've asked them if they do custom sizes and they don't. I'll look into the Keis, thanks.
A 25 mile commute at anything less than 5C the cold really comes through even with shirt, winter liner, bike jacket and waterproof layer on the top half (and I have heated grips and muffs). If "good gear is good enough" then what makes of jacket would be recommended for keeping that cold out?