Iteration 3 of the exhaust...
I opted for the Flowmaster exhaust as it had a slightly higher volume and a longer flange to attach it to the existing pipe.
I hated the black though so a couple of coats of High temp paint and its silver. Of course explaining to my wife quite why I needed to bake my exhaust in her over for 2 hours was rather entertaining.
I used a 6" stainless 304 clamp designed for diesel smoke stacks to make a second support mount to the engine. This stiffens everything up nicely and allows all of the exhaust to move with the engine.