If you are going to put luggage over the passenger seat area why have a Bip unit, the one Dave at H.C.Ractech does is for a road bike & he does a good paint job to your spec for a good price.
Have attched a pic of my trackday seat unit, complete with rear light holes, Dave has a bracket glassed into the seat unit so it accepts your bip brackets etc, have got spare brackets for my unit & it know takes all of one minute to swap from twin to single
Chris.
[Edited on 3-2-2006 by chris.p]