3 footers...which one?

I will be getting 2 granite slabs (18 X 18 X 1.3). My Quad 21L loudspeakers will stand on these slabs. I have zeroed in on 3 footers under the speaker spikes:

1. Herbie's Cone/Spike Decoupling Glider (brass)
2. Herbie's Extra-Thick Hush Puckies (brass)
3. Waipuna Sound Myrtlefeet- Set of 4 (tall feet for spiked components)

My main intention is vibration control and raise the speaker height. What are your experiences with these products?

If you are interested in the Herbie's products, give them a call. They will talk to you about what you want to acheive and recommend their best product for the task, even if it's the less expensive option.
I wouldn't put a brass spiked foot directly on granite. Instead use the myrtle wood on the granite and put brass spikes onto them. My favorite spikes were very heavy custom made footers from Edensound. He may still be making them, they were inexpensive and very good, with screw tops that fit my gear.
I am in touch with them. Their products indeed have good reviews. I am wondering if I should get the regular Hush Puckies and place them on the Waipuna Myrtlefeet (regular size), with the speakers sitting on the Hush Puckies.
Granite rings put SYMPOSIUM SVELTE SHELF on top for much better sound,more bass, better stage,better imaging,etc.
Thank You for the suggestions. They are expensive.

I have Herbie Audio Lab's Extra Thick Hush Puckies on order now. They have the vibration blocking dBNeutralizer bonded to the base. I read a thread that even Jim Smith (from Get Better Sound) recommended Herbie's products. Besides, I read so many threads on this forum and others where people have nothing but good to great experience with Herbie's products.
I would use the Herbies Gliders, as they make it easy to move the speaker around to set the correct distance and toe-in. Once you have that dialed in, you might want to try a different interface to achieve a different sound, but I would start with the Gliders.