best matching speaker stand for B&W 805 sig

These folks make nice stuff.
I believe they have one matched to the 805s.
http://www.hne.co.uk/

I haven't experimented, but I have the Sound Anchor stands for my S805's and I am very pleased with them.

Atlantic Tech Reference XL 24" (Fat column type)
or the Target R series
or the B&W stands

You might try the Sistrum SPK-24 or SPK-28 speaker stands (http://www.audiopoints.com). I believe that you can audition them in your home.

I have B&W Silver Signatures (the 805's grandfather, the $8000.00 all silver wired monitor from 1991) and spike both the stands and the speakers with their AudoPoints.

I have the Sistrum SP-6 six shelf equipment rack which is fantastic, and I plan on going with the SPK stands when I quit upgrading my equipment and the money becomes available.

As far as how tall they or any stand should be, it's according to your chair. Your ear should be on the same level as the tweeter.

Good luck! A good stand will tighten up the sound very nicely.

Another alternative to Sound Anchor, Target R4 or the Atlantis XL stands are the Skylan Stands.

They are custom built to order. They are just as solid and heavy and more affordable.