20” stands seem kinda low as the tweeter will likely be below your ear level. These are not aggressive speakers in the highs so I’d think you’d want the tweets more on ear level that would likely require the more common 24” stands. I’d look for something like these that are very reasonably priced and sand/lead fillable to add mass for better sound, and I agree spending $1500 for stands for these speakers is a bit silly when there are many much more reasonable and very good stands available out there.
https://www.monoprice.com/product?p_id=31264
Here are a couple from Audio Advisor…
https://www.audioadvisor.com/new-pgds200-24
https://www.audioadvisor.com/new-pgds400-24
Hopefully this shows you there are very good options 80% - 90% cheaper than the $1500 stands. Great speakers BTW. Best of luck.