I dont love aperiodics, I feel it feet well to some Dynaudio drivers, but by the good result I listen on this video this project may sound good too.
If I were made a B200 box, I surely use the bigger possible box, i.e. the sealed 100litres as recomended by Visaton, cause a bigger box offer more bass.
If a two way: I would put the B200 as OB and more a boxed Eminence woofer.
Of course it is just IMO.