[MKS427]

Price range? Authentic? Big Brakes/wheels? Street mild or wild? Track car? Autocross? Tall person?
Quick general info:
Classic, no longer in production, 6" longer wheelbase plus wider mostly in cockpit for larger people.
Superformance & Backdraft, both produced in South Africa, consistent quality build as they are complete painted rollers minus motor and transmission.
ERA, tend to be more correct to their original counterparts.
Factory Five, smaller cockpit than most. Quality varies low quality donor car builds to all new parts including suspension. If you are thinking a track car, check out their Challenge car. If you are going to track, the 3 link is recommended over the IRS, but you will want a full floating axle conversion to prevent pad knock back. An issue I am sorting out right now.

You should be able to buy a nice used Superformance, Backdraft, ERA, etc for the same or less as a new FFR complete kit of similar quality.

Hope this helps,
Mark