Stuart suggested turning the chamber on it’s side:
This would require a custom stand, but that’s easier to do than custom vacuum equipment. This also would require an adapter from the turbo pumps flange to the 10″ conflat (likely ~$500)
Also, not sure if the two 27″ OD ASA(rubber) flanges would work as well without the assistance of gravity. I image this setup would require a shipping strap when not under vacuum.
Also having a rounded bottom makes mounting things more difficult.
Prometheus Fusion Perfection 
if you turn it on its side, do you need to use the hexagonal top section? And if there is no top, I would think the 27″ blank wouldn’t need a flange.
no, you do not need the hexagonal section.