A few year back now, I decided to start a biker army using the then-new Codex Space Marines. I built and painted - with chapter badges, unit markings and so on. The army ended up as about 1500 points, with numerous unique conversions.
I've actually barely played it, though, and reached the decision to sell it off on EBay - feel free to take a look at the pictures, and maybe place a bid if you're interested.
Here's the link: http://www.ebay.co.uk/itm/RAPTORS-CHAPTER-SPACE-MARINE-BIKER-ARMY-PRO-PAINTED-1500-POINTS-40K-/261174986816?pt=UK_Toys_Wargames_RL&hash=item3ccf3e0840&_uhb=1