I don't think I have enough to fill this space.
I am really picky.
I like silence, and reasonable temps, as well as stable current/voltage for over-clocking.
Modular cabling is nice, but not necessary.
I thinks PSUs should try to conform to standard form factors as much as possible, for...
I know I'm too late, but if you ever do this again, you should use thermal adhesive, which has better thermal conductivity than glue, and will still hold your components in place.
Some people will also mix quantities of thermal adhesive and thermal paste together, to still firmly bond materials...
Unless you're sending audio through S/PDIF, won't you get more audio channels with HDMI instead?
Some monitors are picky about HDMI input though, try fiddling with your output settings till it works.
It's kind of a niche product, but if you don't want to part with your beloved case just yet, you could get a ThermalTake BigWater kit.
The 760is and 780e both mount in standard 5.25" drive bays, and although they are large, case modding may not be necessary to mount them. The 760 occupies 2...
If you need low profile cards, the best I've seen from ATI is an HD 4350, I think you may be able to get up to a 9800 GT low profile from NVIDIA as well.
What form factor will this be?
NVIDIA cards with HDMI will need to be connected to an S/PDIF header to output audio.