Yes your weber 45's should work on the Duratec, you will have to have them re-jetted though to suit that particular application. We did some development with Duratecs running 48's for Hot Rods and they made about 250-270hp. Electronic fuel injection would be a better way of doing it because you could achieve the correct fuelling across the whole map. Having carbs is a bit hit and miss really as you have to compromise most of the time, e.g slightly rich at the bottom in order to be perfect at the top, but it depends on the funds availible as the car would need converting over etc. It would be much cheaper to go with the 45's as the fuel system in the car is for a carburetted engine already. Ignition wise, check out a company called SBD, as much as I hate plugging the competition lol, Steve Broughton should be able to sort you out with an MBE ECU (either a 967 or 992 I think) that will completely control the ignition. He's done alot of work with Duratecs so he should be able to help. You need to use the std Ford crank sensor from the duratec along with the water temperature sensor, Ford coil pack and leads. This will then provide an ignition map based on engine speed and water temp. For a more advanced setup, a throttle pot could be fitted to the carbs in order to form an even more detailed map but it should work fine without it. Hope this helps! Good luck!