so, to put a sixer in drop B with standard strings would involve tuning the 5 highest strings up a whole step. This isn't a problem for your neck (no time like the present to learn how to use the truss rods! they're there for a reason

), but I would be concerned about standard strings surviving at that tension. I foresee broken strings unless you go with a much lighter gauge for those higher strings. Something to consider if you ever do decide to use that tuning (and if you do, may I recommend circle K strings? I just started using them and am extremely impressed!)