It sounds like you've got a fair grasp of what's going on. I will say-
With almost every decision about these cars there is a compromise of some sort. Whether you're looking for a boulevard bomber or canyon carver, something a little more docile that will zip around everywhere or a car more 'authentic' looking with a period size and look engine, stock size tires/wheels and drum brakes (I really don't understand this 1, but as Uncle Stan says, it's a big tent and there's room for all) you have to decide what's right for you. That's a big part of these cars, I guess- being replicas, originality isn't as important for some as it is for others, and there's no wrong way to do almost anything (except for the grey Sema Speedster, of course, with it's French Bordello/Russian Kremlin themed interior!).
We just have to decide what we want, and how much money we're going to spend to get there. And while no Speedster can truly do everything, the more money we spend, the closer we are to that 'perfect car'.
In case you hadn't seen the Sema car- a nice enough looking car from a distance-
but who does that to the interior of a Speedster?!