No comment on "material" as the only "fillable" stands I own and have used/liked are Target HR's (once briefly used a pair of inexpensive "fillable" metal stands that were crap, but forget the name).
Not many 20" stands available right now (it seems based upon a quick Google).
Skylan (from your list) is a bit over budget @ around $340/pair delivered for the SP-20, but due to the large 8x10 top plate (and their reputation) they may be a good readily available option.
Did Pangea and Mono ever offer "decent" 20" stands?
My only comment on the Skylan's is that the floor spikes would seem to "only" be adjustable from the bottom (same as my older Target stands) and leveling the Target's was a PITA.
This said, I didn't go through the trouble of leveling them properly until I found their proper placement by ear (this was with Reynaud Twin MkII's) so it was a reasonably painful ordeal (back then when I was younger, hipper and smarter;-).
As far as "fill" goes I tried gobs of stuff (lead shot/lead shot + sand/sand) and I ended up with the stands filled 1/3 of the way up with silica sand.
However, on cement slab floors (mine are wood frame filled with plaster) for a friend we ended up using sand and lead shot, so like most everything else in this hobby - it depends.
Anyway, interesting speakers - good luck.
DeKay
Not many 20" stands available right now (it seems based upon a quick Google).
Skylan (from your list) is a bit over budget @ around $340/pair delivered for the SP-20, but due to the large 8x10 top plate (and their reputation) they may be a good readily available option.
Did Pangea and Mono ever offer "decent" 20" stands?
My only comment on the Skylan's is that the floor spikes would seem to "only" be adjustable from the bottom (same as my older Target stands) and leveling the Target's was a PITA.
This said, I didn't go through the trouble of leveling them properly until I found their proper placement by ear (this was with Reynaud Twin MkII's) so it was a reasonably painful ordeal (back then when I was younger, hipper and smarter;-).
As far as "fill" goes I tried gobs of stuff (lead shot/lead shot + sand/sand) and I ended up with the stands filled 1/3 of the way up with silica sand.
However, on cement slab floors (mine are wood frame filled with plaster) for a friend we ended up using sand and lead shot, so like most everything else in this hobby - it depends.
Anyway, interesting speakers - good luck.
DeKay