Hi Brian and welcome to the madness.
I also went through the exact same evaluation you are currently involved with. I got hooked with this slice of automobile passion through the FFR video, and started my research from there.
FFR make a nice kit that provides a lot of latitude as to how to complete the build - small block motors are not uncommon in the big block body. Be aware that only a small percentage of FFR's are completed with the 100% donor-car route. Some peole feel the FFR misses the lines of the original car - it is called the "perky butt" line - due to well...its perky butt.
The ERA will cost you more $$ - period. However, the upside is unquestionned authenticity in the areas you can see, and an exceptional chassis/handling - and when you think about it - this is the soul of the car. The ERA will show much higher resale value down the road.
As for the 427, well Ernie, I believe the 428 is a much better street motor, but the key point being they are both big block FE motors and everyone is in agreement oin this for an ERA - unless you look at the FIA small block model by ERA.
The best advice - study the websites in detail and visit both factories - they both offer a good product, but, like Ernie said, are serving 2 different parts of the market.
If you are only a few weeks into your evaluation, you have a ways to go - there are many other alternates as well - I was really partial to Unique - a good middle position between the ERA and FFR. And then there is....oh well, take your time....remember - enjoyment is 9/10's anticipation....
Good luck,
