I have not personally heard of any other solvent being run in a CSL, other than butane. There has been some talk of propane and hexane, but apparently they have their own set of problems.
Your first question when purchasing a CSL system, is if you want, or need, a ANSI/ASME certified system that meets all food handling and safety issues as well as any potential fire and explosion safety protocols. If you are producing for the retail or medical market this is paramount.
There are, very few, certified systems on the market, but fly by nighter type operations abound. Do your homework. There a couple systems worth while to consider, that seem to be a little more superior than others and a few that are not so much. Really depends on your needs.
For a certified system I would consider, Terpp Extractors. I personally have chosen Dabzpro Extractors, they seem to have the best bang for the buck and far superior to most others available. There are others that appear to be working as well. Beware of the fly by nighter's or cheap knock offs. Service is everything in this industry and you definitely want good customer service and technical support for what ever system you choose.