MarionLH, yes (several) and imo yes (sort of).
Sorry, I'm away from home with limited access to supply links, there should be some around CotI somewhere, possibly my own included.
I say sort of because the way I built my B2-B5 conversions attempted (mostly succeeded) to keep the overall ship the same. So I usually take the purifiers out of fuel tonnage (which is reduced in B5) and keep the cargo and the rest the same. I find very often the B2 drives and fuel can be made to work as B5 drives, purifiers, and fuel. That means most if not all B5 ships do indeed have purifiers, even if the B2 versions didn't.