I was able to get the dual 2.5" rear into my 836A. You have to remove the entire back window, and cut off and smooth the edge where the panel blank is attached on the left, so you are just left with the rectangle for attaching pci cards. Then you have to grind down the threaded bits for the 2 or 3 screws the protrude into the bay. It's a tight fit but it works. The screw on the right doesn't match the hole, you cold drill it a few mm up to fit, but i left it out. the screw on the left kinda fits I was able to screw it all the way in and the bay seems locked in even with just friction holding it. For the front, the only downside of the chenbro is it's 3gbps, fine for spinning rust but less good for any ssd. I used the icy dock dvd adaptor since it doubles as a slim fdd if you take the side off. You can also find the backplane to fdd cable on eBay for cheap.
SUPERMICRO CBL-0210L FDD DVD 4 PIN POWER ADAPTER CABLE 8CM 3.2" 24AWG is the one I used, $6 each.
/yay