Is it possible to get an instrument rating in a cub or will the instructor not be able to see enough of the instruments? Should I just rent a 172?

Thanks!

You should be able to fly simulated IFR training. You would not be able to file and fly actual without the instructor having instruments in front of them.
I just completed an instrument proficiency check ride in my Husky.
No problamo.
Steve

The Super Cub is not approved for IFR flight, per the Type Certificate. So, definitely no actual, and you cannot FILE IFR even in VFR conditions in that case. You're also going to be pretty limited on navigational options with most Cubs, though I have seen some pretty amazing instrument panels on Cubs.

MTV

Ah, Cadillac of cub country, the Husky!

What those guys said, the airplane you take your checkride in has to be IFR legal. That is not to say you can't do some training in your own airplane though.