Don't you know all the oxygen molecules in a regular iron stand interfere with the sound envelope and produce a sub-par frequency response? Fill it with lead, sand and stones if you like, I'll settle for nothing less than lab-produced ferromagnetic fluid as filling for my stands.
I'd go with HKKens advice. Ap Liu stuff is mostly cheap garbage and so is the China made crap sold on Yahoo. If you got something High End pick up something decent or you will regret it later.
unless you have some really high end equipment, thus need for high end solutions, Linn are more mid high range, thus in probable accounts, filling with expensive stuff may have only negiable effects, even what hifi forum people recommands sand or lead shots
What Hi-Fi? Sound and Vision - Which sand is best to fill speaker stands?
What Hi-Fi? Sound and Vision - Speaker stand filling
talk about ferromagnetic fluid, have you ever seen this liquid when close to a magnetic speaker, it's like a 3d spectrograph of the sound waves, it wicked, look it up on youtube.
Have you considered DIY?
Talk to your local scaffolding contractor - or to the foreman of a local building site, then get him to chop two lengths of thick bamboo tubing from a suitable (at least 4" diameter, though 6" would be better), seasoned bamboo section.
The length of each section is determined by your required speaker height from the floor. Make sure the cut ends are "squared off", to avoid slanting stands, then simply place each bamboo end on a cork table mat, draw around the tube with a pencil, cut out the circular section and glue it to its matching bamboo tube with contact adhesive.
Et voila, sturdy, lightweight, speaker stands - and if you're worried about stability, stick the wider end of each tube to a larger wooden disc or square - which you can find in Apliu Street or Upper Laskar Row markets.
You can even use self-adhesive Velcro patches on each speaker base, plus corresponding velcro patch on upper cork disc, to stop your speakers "walking" off their stands.
Simple, cheap, sounds good and - above all - imaginative.