Not much resemblance at all. The F2 is longer, narrower in the front, has no clip/cab mounts in the same location, etc.... It would be a step backward, IMO, to try and make an even older frame work for a '55 f100. I would suggest either a newer frame, or graft a newer IFS, and/or IRS suspension to the existing frame.
Not really, the '55 frame is 34" wide from front to back which is the same for several years (up through '79 for certain models) that can be made to fit. There are several article in FTE that can help. Start here: Front Suspension Alternatives for 1948 - 1960 Ford Trucks, Part One .: Articles Just keep clicking on each article part to get a vast array of options. The end result is basically up to you and what your intent for your F100 is. Slammed street rod, air bags, stock but modern, etc... whatever floats yer boat.