I would suggest the you take the time to decide, what you really want, why you want it, and how you are going to drive the car.
There are a ton of great engine options for your car from the vintage style small blocks all the way up to the SOHC and Kasse Boss engine
Is there a particular reason why you arrived at 427cu?
Are you talking 427 FE or windsor based SBF?
The good old iron FE blocks are tougher and tougher to come by. A popular option is the stroker 390FE block 445cu
Both the 445W and 445FE are about the same price 12K +/-
The iron block FE will weigh a little more.
If you track the car a lot, you may want to stick with the small block. It is lighter dollar for dollar.
Since you are removing the shock towers, you could even consider the Coyote.
On chosing a builder. Once you have decided on an engine, then do the research on the builder.
There are lots of good ones around. You don't have to be bigger to be better.
I still get excited when I see a killer 347 stroker dressed as a plane jane 289.
The 289 based blocks have a really low piston speed, and are very durable. The more that you stroke them, the faster your piston goes, though.
I'm getting Brent to do mine. He's a serious ford guy and always easy to get in touch with. http://www.b2motorsportsllc.com/engines.html