If you are looking for an actual Bridgeport power feed, you will need the proper lead screw for it. The gear driven feed had a mad long screw for it and the 6F/8F actually had shorter screws that coupled with the feed.
Most power feed brands (Servo, Dynamo, Align, etc) will make kits for your standard Bridgeport screw. It just all depends on the $$$ you wanna spend and do you care what continent its made on. I know that Servo makes like 95% of there stuff in Ohio (been there, I think the circuit board is the only part made in Mexico, everything else is done in house) and I get alot of my Align parts from Cali, but I dont know where theyre made.
Jon
H&W Machine Repair