I have a running kernel with the same kernel version of that in the kickstart that contains the Buslogic driver which would enable me to install a vmware client using kickstart.

Is there an 'easy' way to take the initrd that contains the correct drivers and inject these into the initrd of the kickstart kernel? Or does anyone have a kickstart initrd available with the Buslogic drivers for an 2.6.9-55.ELsmp kernel?

to follow up to myself this was in actual fact super easy, all i had to do was add

driverdisk --source=http://xxx.xxx.xxx.xxx./cobbler/ks_mirror/drivers/dd-RHEL4.img

to my kickstart template and it was away!