Couple of thoughts.

Original 27 T bodies and faithful glass reproductions are very tight. I am 6'2" tall and I don't fit.

Zipper in Colorado makes a 27 T "bucket" that has been stretched length wise. It has good room if you are not to big across the buns. Zipper offers a frame and a rolling chassis option. Zip has a web site. Do a YaHoo search.

Stinger in Indy offers a stretched cockpit 27 with integral turtle deck (picture). I have not seen one myself but a very picky acquaintance is having one built so I'm thinking they are fine. They also offer a chassis. No web site that I know of but you can get their catalog by calling (317) 791-8537.

The Zipper and Stinger bodies have doors. Speedway is a step over.

PolyForm is in California. The shipping will kill you. Speedway is in Nebraska. The shipping will blead you white.

At one time there was an outfit in Maryland called A1 Fiberglass. I have not seen one of their ads in several years. They made a 27 body. You masy be able to track them down.

When I was a kid you could by a running flathead engine for $15. There is a book you should be able to find at Barns and Noble or one of the other big book stores that takes you through the process of building a "traditional" hot rod flat head engine today. Every step is documented with it's cost noted. I won't quote figures but if you can find the book you should be sitting down when you brows through it.

Why don't you consider an alternative power plant? Like one of the 4 bangers out of a Chevy II or Nova. They make good power, look neat, are relatively inexpensive, and they bolt up to a variety of stick and automatic transmissions.

I just started rebuilding a 61 all aluminum Olds 215. I'm going to adapt it to a 700R4 auto (from a 2.6 V6 Chevy S-10). It is slated to go into a chassis of my own construction. When I conceptulized this project I was pretty much set on using the Zipper body. But that was before I saw the Stinger. So I'll finish the engine and transmission and make up my mind when they are ready.

Good luck to you.