A lightweight bike would be nice

I think sub-7 would be nice. I really don't know. Have to weigh the ones I now have. I think the lightest at the moment is one of the roadies, at 7.7 or so kilos (w/o pedals).

A decent target.

Sub 7Kg could be done without sacrificing stiffness, and without buying some of the silly money weight weenie components.

I also feel (IMHO etc.) that if you get the stiffness right. Such a bike would feel far lighter.

Frame = Dolan Seta
http://www.dolan-bikes.com/track-bikes/frame-sets-track/dolan-seta-framesets
Seatpost = KCNC Ti pro light
Stem = KCNC Sc wing
front hub = Crit VR road hub (http://www.superlight-bikeparts.de/)
Rear hub = royce
Rims = Klinin XR 200 (http://fairwheelbikes.com/kinlin-xr200-clincher-rim-p-1214.html)
Bars = KCNC Sc Force. (http://www.burls.co.uk/shop/kcnc-sc-force-scandium-road-bars-318mm-os-440mm-p-84.html)
Saddle = SLR Ti
Spokes = SAPIM CX-ray rear, DT Revolution front.
Inners = Latex
Tyres = veloflex corsa.
Crankset = Rotor Agilis (or 3D) (partly as you can buy them separatly), with SS chainring (need some bodging here for chainline).
BB = Token tiramic Ext BB.

That'd be pretty dam light, not too pricey, and dosent contain any dodgy cheap carbon.