The Kogswell looks like a wicked bike go for it!
On the other hand I don't really get the 650B hype (my opinion has little value: I can barely feel a difference between a 26" and 700c wheel), and I'd be nervous in having a super nice city/utility bike locked around... My solution was to take an old MTB, fix it and fit a huge basket and moustache bars. It serves the purpose quite well. Or simply get a nicer portuer rack on a cheaper bike...