That's a little narrow. Rim Width should be the same as the Tread Width to get the best performance from the Tires. Manufacturers usually give a rather wide variance on what width rim a tire can be used. However, they want their tires on your ride, and your money in their pocket.

 

What do you think about 5:13 gears? Would that be to low? I might switch to 37" tires in the future I'm not sure yet.

 

I have/used a set of 5.13's w/P-Track. And if you're going to do rock, then yes. The more revs per revolution of your wheels is going to smooth out hopping over those stones.
But just keep in mind, the higher that number gets (hi-ratio) the farther you get from having a street/hiway ride. Most of the Rubies and other little rock hoppers they build, are used only for that/climbing.

 

Ok thank you. I will stick with the 4:88's then.