That photo isn't mine, but i think the guy posted some measurements in his thread. I'll see if i can find it..
EDIT: http://www.overclock.net/t/1563907/build-log-unit-3-1-tri-sli-matx/10#post_24165622
Thanks for the link. My next question was if single-slot SLI bridges were available - and it looks like at least flexible ones are.