Here is a link to the Holley/Hurst hoop and transmission cross member.
Hurst 67520001 Hurst Transmission Crossmember & Floor Brace for 1967-1976 Mopar A-bodies
Tthe "Hoop" I refer to is missing in your photo and 72bluNblu shows going over his T56. The sheet metal they refer is the patch panel to replace the areas you cut out to fit the transmission in the tunnel.
My TKO swap was $3350 (install by my dad and I) about 5 years ago mostly because I started with a 4 speed car and didn't need a drive shaft (stock length was perfect), Flywheel, or pressure plate (I just needed a disc to match the spline) and retained the stock clutch linkage. I will the aluminum bell they sent liked the 72-up Z-bar pivot if you're going that route. I love my TKO600 and had a Tremec 3550 before and both shifted smooth and were fun to beat on.
That TKX isn't saving any work over a TKO or T56 on an A-body. It was probably made for the cookie cutter 1 wire Chevy crowd.
