Bill started off asking about cars, has decided on Superformance and seems to be now in between buying one already completed and buying a roller and doing the engine himself. To his credit he's gone through the process and so it wouldn't be fair to turn every one of his topics into "why are you buying that, buy this instead".
I think the big block vs small block is more of a religious issue. Well, cost too. The bored Windsors are relatively less expensive than any of the 427s, original or new build. Shelby Engines makes a bang up aluminum block side oiler but it's quite pricey.
There are lots of Roush stories in the forum. Mine is one. Mine was the 427IR fuel injection that took quite a bit of work to get to work properly at high altitude. Once I got the DFI system calibrated I liked the engine. Mine did not consume any
oil let alone excessive
oil, yet others have reported issues of excessive
oil consumption and even nightmares about getting the engine fixed. Other builders here will do a Windsor 427. I won't get into who to recommend because I have no personal experience.
As a first time owner I'd strongly encourage you to look seriously at one of the cars on Cobra Country.
Good luck! You'll love the car. It is by far my favorite car I've ever owned.