Winnebago is using the Sprinter to make A's (Via/Reyo), B's (Era), and C's (View/Navion). The c's most like a B+ would be View Profile and Navion IQ, though Winnebago has not used that marketing term (from Gulfstream originally) to describe a C without overhead bed.
There are actually quite a few Navions and Views out there, been making them for something like 8 years, but the IQ and Profile are more recent and rarer. If the idea is to get a Sprinter under you, I suggest you look at them all, new if you must in order to find them, to decide how much space you want for travel. The true B, the Era, is slimmer and gets around better. The A, C and B+ styles are roomier, the A probably roomiest, and all about the same size outside, 24-25 long and just under eight foot wide.
Sprinter B's and B+/Cs are available from other manufacturers, again going back 8-9 years, Gulfstream about the oldest. Earliest models had the overhead bed, it is only recently that U.S. manufacturers have moved to what in Europe is called the "profile" motorhome style on a Sprinter.