What I meant about B versus P in German-origin names is that they were often used interchangeably in the original records: one clerk would write B, another clerk later would hear it and write it as P. (Same with D/T, and to some degree K/G. F versus V gets into some of the same confusions as S versus Sz, where the problem wasn't different pronunciations, but different sound-to-letter assignments.)
I'm aware that search engines can be very literal, but that just means that you have to try every variation that you've seen or can think of, and make use of any wildcard options offered -- search for Ant* instead of Antal, for example, to turn up the Latinized records where it's Antonius. These strategies are just as useful in "smart" searches (like FamilySearch) as in the dumb ones, really, because they also help work around mis-indexed data.