Bro there's two showrooms in pindi, car craft and import heaven. Car craft currently has a 09 R1 in yamaha blue but you mentioned that you're only interested in 04-08 models. Import heaven has no R1 or ZX10r in stock for now but their new stock is due to arrive soon. Car craft is also bringing some new bikes from dubai.
In lahore there is Will bikes and Bashi motorsports. Bashi motorsports has a very nice red/white 08 R1, i think you've probably seen the ad on PW.
Will bikes have a 05 gsxr1000, not sure about the demand.
Finally, in karachi, there is Burnout motorsports. They have a 08 zx10r and 05 & 06 R1.
P.S. Whatever you do, do NOT go for the yellow/black R1 for sale in islamabad. It's been crashed and rebuilt.