KW V3's aren't even a track coilover. They're too soft from the factory, need to be rebuilt frequently and aren't all they're cracked up to be for the 370z.
I know you said you don't want BC but i've got friends tracking those on 350zs and 370zs with Swift springs and they're pretty happy with them.
Powertrix seem to be a pretty good budget coilover for street and some track use. I have a set of these on my Z31 300ZX.
Also there's a new company with an offering for the 370z called
Annex Suspension. They actually rode with me in my 370z equipped with Mines Ohlins ESTA coilovers to get a feel for them so that they could engineer some of that into their design.
I know both the owners behind these two companies and the design/engineering philosophy behind their products. I highly recommend either of them as a budget coil over.
Stay away from Megan, Godspeed, Tein, KW and HKS, the feedback i've gotten from people about those are usually around quality, adjustability and a poor ride.