The Pocket Rocket will use most other fuel cylinders (Jetboil and Snow Peak were the other ones I used.) When I used mine (before I switched to the Jetboil Sol), I preferred the MSR cylinders because they were a bit wider and lower than other brands, which made them a tad more stable. However, I never had tip-over problems with other cylinders, either.

I always found that any store that sold Jetboil or Snow Peak canisters also sold MSR canisters, so getting them was never really a problem. The only reason I ended up trying the other brands was that the outfitter had temporarily sold out of the MSR canisters (big Scout weekends created a "run" in both cases.)

You may want to look at the MSR MicroRocket - it's just a more compact version of the Pocket Rocket (of course, compact equals more dollars.)