I've got a customer who's 6ft10, makes his 23" Spesh Rockhopper 29er with 400mm seatpost at max extension, and riser bars on it, look like a BMX! Haha.
MrTall off here rides a Kona honzo 20"Long (they do that rather than make a 22" I think for stand over reasons) that at 6ft7 seems to fit him quite well. He's got the world's longest legs though!
Stanton Bikes new Sherpa frame is going to come in a 21" size, with a VERY long top tube. Dan told me he's designed it to fit a mate who's 6ft6 thereabouts and long of limb. Gotta wait a few months yet though!
21" Inbred 29er (or a Scandal) would be the obvious cheap choice. Geometry is a bit too steep though IMO (I owned one), needs updating.
Solaris in an XL looks a bargain at the moment at 25% off, should be big enough at a push too.
As for forks... SID's really are for lightweight super skinny race whippets. They're flexy and I wouldn't recommend them to most people, at your height (even if you're skinny) you're going to find them quite a flexy proposition. Reba's are better, but still not the stiffest. I'd look at something like the cheap 2012 Revelations on CRC right now as although still a 32mm fork there's more material in them, or the X-Fusion Slide. Both forks are highly adjustable travel wise, noticeably stiffer than a SID or a Reba, and don't cost the earth. Running one of each right now and impressed with both.