I guess I’d start with how much horsepower are you looking for, and what types of work are you looking to accomplish that the B2100 can’t currently do?
Some examples that come to mind are loader lift capacity, PTO work like a tiller, mower or snowblower, or ground engagement like box scraper, rear blade, cultivator, or middle buster.
Some of those answers will help guide whether you should be looking at another B, an LX, or L series.