Gravity rainwater filtration...Berkey-nope. Rainfresh-Canada only? What are you using?

I'm looking for a gravity fed Berkey style countertop filter. I have ample rainwater and a filtering a couple gallons a day for drinking/cooking would be liberating. Rainfresh SM4 seems to be highly rated but I can't find any US resellers. There are a lot of other ones I haven't heard of. Any direct experience with other brands? I particularly like the fact that you can clean the Rainfresh filters and they provide a measurement tool to show when to replace.