Buying sourdough starter

I would like to start my own starter, but since I am coming to the US for a visit I thought I would use the oppurtunity to buy a sourdough starter (or two) . 

I googled and read a couple old threads here. Sourdough International was mentioned, King Arthuer, and NY Bakers. 

Looking at the sourdough international website, any thoughts on which starter(s) might be fun to start with? 

Their homepage mentions the Poland one as a new product and recommendation.