There are gel grips available but I do not know anyone with them to ask on the long term effectiveness or how if heated elements create any problem. The BMW styled grips have the following part #
Try Argyll that way you can see the BMW grips on the Adventure bikes / tour Bikes and what ever they have in their acces dept. If need be go up to Honda Extreme and ask them.
BMW part numbers: They should have some in stock so you can play touchy feel with them.
Left: 32721458395 (Non Heated Grip, Left, Concentric Groves, Open End - 32721458395)
Right: 32721458396 (Non Heated Grip, Right, Concentric Groves, Open End - 32721458396)