@skyking,
It's up to you what kind you use, but I do have some observations/opinions:
Bar end weights typically are not useable with factory heated grips, from what I've seen, and the grips appear to be shorter.
The heat controller as-fitted may take up space you'd rather use for some farkle that needs to be seen more often, like a GPS or something.
They are $$$$.
Using an under-grip style allows the use of any other type of grip that you choose, if you're concerned about that. These types are also way less $$$, and really not hard to install.
At the least, if you have some confidence in your garage skills, I recommend doing the job yourself.
Good luck, YMMV
Shane