Took me a bit, but I found the trilogy I was lookiing for. It is not SS/HG, but a continuation of the HP series just after GoF. Yeah, it was written that long ago. And it's *damn* good! I met the author in person at Azkatraz :D Severus lives, gets his very own witch, mostly happy ending for all, but the sacrifices, twists, turns and horrible lessons Harry has to learn are far more real and, well, horrific than anything JKR wrote.

I highly recommend it if you haven't read it yet. And it's *LONG!*

The Psychic Serpent
The Time of Good Intentions
The Triangle Prophecy

http://home.arcor.de/mark.halpaap/