Full-frame DSLR adaptor choice

[Stratis]

So I'm really hoping to start imaging on my C8/Canon 6D full-frame combination, with Celestron f/6.3 reducer in the train.

The issue I see with my images currently is the expected vignetting on such a large sensor, possibly made worse by the narrow T2 aperture through which the light must pass. 

Can anyone recommend to me a suitably short, wide-aperture adaptor for this setup? I'd like to avoid T2 as mentioned.... I had found the Astro-Engineering AC696 MaxDSLR adaptor but have not been able to find anywhere that stocks them.

If anyone has an unused AC696 MaxDSLR I'd take it happily

~Paul

[Xplode]

With a 0.63x reducer your image circle is max 30mm so a T2 adapter won't create any more vignetting.