of those you listed, i'd recommend the paddywagon.
while it's not my favorite, you mentioned you're going to be using it primarily as a training bike; the dual water cage bosses are probably a good idea. the mark v and steamroller only have one, the bareknuckle has 0.
besides that, it's the most like a road bike (geometry) of the ones you listed, and is actually made of pretty good tubing; the same dedacciai com tubing as (i believe) the bareknuckle, which is pretty good stuff.
i've always felt the steamroller was pretty mediocre, and the bareknuckle (while a fantastic frameset) isn't really what you're looking for. the mark v is a good bike too, but probably not the best for your needs.

go with the paddywagon.