Julian > No I am going by old pictures, so perhaps this has changed, but Omega only seems to have 32bit PCI sockets. If that is the case reprogramming the FPGA although it may allow for 66MHz operation it still *wont* support 64bit operation as PHYSICALLY there is nothing to plug the 64bit card into (ie., no 64bit socket)!
You'd need to redesign the PCB to support 64bit signals, fit 64bit sockets and *then* program the FPGA's to support it - or have I missed something ????