Amazingly enough, you're going to find that ERA owners will jump on here and say you need to go with the ERA. FFR owners will give you tons of reasons to go with the FFR. What are the odds?
I have an FFR and love it, but here's my advice.
What's important to you? Originality? Performance? Value? Is money no object?
Personally, I wanted a car I could go out and have a good time with. It wasn't going to be an "original" Cobra, so I didn't care if it looked exactly correct. I wanted it close, but didn't need to be perfect. Outside of the fairly small Cobra community, 99% of people can't tell the difference between my FFR and most other replicas. Are some of the other kits the "Cadillac" of Cobras? Maybe. Are they "better" than the FFR, or even the ERA? Maybe. That's debatable. Lots will say the FFR is just as good, or better than, other kits. But is an ERA, or other kit worth an extra $10,000 over an FFR? $20,000? Not for me, it wasn't (probably couldn't have afforded it anyway). But some will pay an incredible amount of money just for a certain look, or to get that CSX number for their car. It's all personal preference.
I'm not trying to sway you one way or the other. I think if you look carefully, you'll be happy either way you go. But the questions I raised are ones you need to answer for yourself.
Steve