Re: a good les paul configuration?
Comes down to personal preference.
Through a cranked Marshall, the 59B is going to sound more like Clapton's '60 Les Paul on the John Mayall Bluesbreakers album: brighter top, more bass, plenty of mids.
Through a cranked Marshall, a set of Alnico 2 Pros is going to sound more like Slash's Les Pauls: smoother, more mids, less bass, less glass to the treble.
Which tone do you want?
Lew