Hey man i just got a suburban and built it up and so far its feeling brilliant. There isnt much difference from this and the majesty apart from that the majesty weighs 2.2kg(black.. think colours are 5g heavier) and the suburban weighs 2.5kg and that the majesty's head tube angle is half a degree steeper and the chainstays are 1mm shorter. The main difference is that is has an intergrated headset which is supposedly better for dirt. As for the bb and cranks i'd just buy bmx cranks and use them and just get a euro bb that fits your cranks(same size spindle) but if you dont want that option there are always Diety Vendetta cranks which are more mtb orientated and very popular which are compatible with 73mm bb shells..heres link for them-http://www.chainreactioncycles.com/Models.aspx?ModelID=30146
In short buy a suburban because at the price they are now you cant go wrong and they are a perfect frame for dirt/park/street
Hope that helped.