AV8 Full memory where to get single rank ddr!?

Hi,
Im sure Ive got 2x1gb of ddr pc3200 in my av8 which is used heavily for
vmware and saves a lot on extra hardware.

Anyway I read that if I put 2 more sticks in of dual rank dimms the speed
will drop to 333mhz from the current 400.

So my question is does anyone know whether corsiar, cruicial or kingston etc
have any ddr pc3200 dimms in single rank config that will go in and retain
the 400mhz rating.

Im after either 2x512Mb dimms or 2x1gb dimms depending on cost etc.

Thanks
Richard