Different string materials can sound a little (or sometimes a lot) different but I've always felt that the gauge is more important (for any instrument, not just banjos). Heavy - gauge strings might sound louder but could do structural damage to some instruments. I would suggest you use the lightest gauge that works for you. Having said that, if they're too light they feel sloppy and tuning gets a bit vague. Whenever you change your strings keep the wrapper for a while until they settle in. Then if you like them (or don't) you'll know what to shop for (or avoid) next time. Good luck with your playing, it's a good way to spend time. That banjo has a lot of good tunes in it, just waiting for you to find them.