When you are buying bottom bracket, you have to take spindle length into account. If you are going to get the Messegner, make sure that the bottom bracket you're getting is 110mm long and it is JIS taper. It is the best to get the bottom bracket that is made for the Messenger, like this one.
http://www.tracksupermarket.com/inde...roducts_id=627

I think the TruVativ that came with the Kilo is good enough...just buy a the Messenger chain ring if you think they are stiffer.