Give me an advice pls =)

[Falcone]

I want to build Edrums to. I've just started and i need an advice

1) What Thickness of rubber and plywood should i get? And what diameter ?

2) I saw one picture with gauge fastening,( download/file.php?id=1594) it situated in center of a pad. But before I always saw two gauges, One in a center an one was displacement. Whats a different ?

3) I've newer seen an Edrums. Will you explain to me whats a different between a sounds when you hit close to center and when you hit in a edge territory, when gauges situated like this (download/file.php?id=1594 )

P.s. Sorry for bad English =)

My drums in a project stage. Maybe someone will give some more advices =)