I've used the Tag CR double hi bars on my GG and found that there wasn't enough room left to get the controls exactly where I wanted them after I cut them down. Sorry, I can't remember what I cut them to, but it wasn't particularly narrow. 29.5" or 30" as I recall. What I would have tried next was Mini Hi bars, which don't need to be cut down as much. But instead I got Trail Tech bars, which are a little narrower than MX bars and have less sweep.
http://trailtech.net/motorcycle_x-bars.html I didn't cut them down at all so they are wider than what you want. Not sure how much they could be narrowed and still leave room to position the controls. More than with the CR Hi bend for sure but maybe not enough for you. There are other choices out there but bars are too expensive to try everything. These bars work fine for me although I also have tall bar risers which are mounted forward of the stock position in the triple clamp. Easier to stand and easier on my wrists.
Regarding grips, if you want a larger diameter you can use dual sport grips like these.
http://store.azmusa.com/noname.html They're bigger and softer. I've used them but have gone back to smaller grips lately. The good thing is grips are cheap and are a wear item so it's practical to try a few to see what you like.
Jon
'01 XC300