I use the cheapie grip heaters and they do fine. On the throttle side I run the wire to the inside and make a little bit of a channel in the grip for the wire to exit perpendicular to the bars, I then form a loop with enough length to allow the throttle to move full range and zip tie the wire in place.
Rocky Mountain had a grip heater blanket sale this fall, they were $9.99 a set. Bought two myself.
