john - I don't know about a supplier of hand guards for the Bonnie. I have them on the old BMW R100GS, and combined with heated grips, they help a lot. By themselves, with the grips turned off, it's still very cold.
Other possibilities - Someone makes a modern version of HippoHands. Here's a sample .... I just picked one of the first ones I found on the web. They aren't beautiful, but I think they're easily removeable. Now I imagine these combined with heated grips, and you'd not be complaining about cold hands. Link at bottom of note.
Another possibility. Gerber heated gloves. Should keep your whole hand warm. Downside: (a) you have to tap into the bike's 12v supply, not difficult off the battery or using Triumph's accessory outlet and (b) you have to run the wiring harness down the inside of each jacket sleeve. If you weren't using them on multiple bikes, I suppose you could have a short pigtail on each handlebar to power the gloves.
Edit - forget what I said about the pigtails, it would make it impossible to use hand signals, etc. What was I thinking?
HIPPOHANDS
Bob
[ This message was edited by: ohiorider on 2006-12-03 11:09 ]