When I posted it last night I had more info in the post.. the forums were pretty laggy, looks like it got mangled a bit. (I hit "submit" and got a time-out back after a minor edit).
The company is Maddoxjets.com
, they have plans and kits that can be ordered (lots of bike builds in the plans section).
Looks like a motor goes for around $850.
The pulse jet is the 2-stroke of jet engines, a series of blasts at the top of the chamber using back pressure for both compression and ignition. More info at Wikipedia