You get 6 bikers in the box, but no special weapons.
Making the most of the older codex, you can have 3 troops choices: DW terminators, RW bike squads or tacticals. The best way (imo) to run tacticals in a DA list is 5 man + special (usually a meltagun) + razorback.
If you're making a lot of conversions from black reach, just bear that in mind. I know a couple of people who use 5 man devvie squads with MLs to add firesupport to tactical based armies.
1 kitted out rw squad (I.e the rw box) will run you in the region of 450 points but gives you potentially 4 scoring units (and a minimum of 3 killpoints). I personally would not take the tornado (you have the bits for a typhoon in the box).
That is, of course, if you want to use the DA book for your army. There's nothing wrong with using C:SM, as the bulk of the chapter are aligned to codex astartes.