DIY help on Speakers Stands

I am working on building some speakers stands for my B&W floor standing speakers.

Here is what I am planning:
4 brass cones per stand.
Some kind of wood base
4 vibrapods on top of the base.
Speaker on top of the Vibrapods.

I have 2 reason for making the stands
1) The tweeters are about 2-3" lower than ear level when sitting. These stands should bring them close to ear-level.

2) I wan to use vibrapods under the speakers and since I have pile carpet under the speakers I need some kind of platform to put the pods and the speaker on. Hence the stand.

My questions are these:

I am looking at a few kinds of wood for the platforms.

1) I can get hardwood wood planks and glue them up to make platform. It would be about 1" thick. To that I would attach the cones.

2) Use 3/4" MDF and paint it. To that I would again attach the cones.

Do you think that there would be any difference in the sound between MDF and hardwood? Reason for asking is that the hardwood costs about 10x as much as MDF.

How much larger do I have to make the stand than the footprint of the speaker? I.e. do I want to have the stand a 1/2" larger in all directions? Or do I want the stand dimensions the same as the speaker?

Thanks in advance for any assistance.

Jeff