Standard street grips... dirt grips are usually closed on the ends, but you could use them if you find some you like, you'll just have to open up the ends so you can put your bar ends back on.
IIRC, there is a ring at the inboard end of the throttle tube that needs to be removed for aftermarket grips. If you decide to install grip heaters while you're at it, there are ridges on the tube that need to be trimmed flush.
I used Pro-Grip gels... I forget the number, but they have a bunch of different styles to choose from and are inexpensive as well as long lasting.