Help in Building Granite top Desk

Hi all, following my newbie introduction post I plan to build a granite top desk with hairpin legs as my first project. This one is probably just drilling and glueing since I haven't bought any tools for my other projects.

The details :
- the 4 legs are around 70cm height
- Granite slab is 1500x550 with depth of 30mm

My plan is to build a desk with wooden top just like normal desk, and then the wooden top will act as base for the granite slab which will be glued to the wood.

I am after more sleek look so I'm looking for strong board suitable for this purpose but still not thick so you can't see the base.

My questions :
- Any recommendation on the dimensions of the wooden base and where to attach the pins to ensure that it is stable and look balanced?
- What sort of wood do you recommend? I'm thinking furniture grade plywood but I don't if they're strong enough to hold heavy granite. I'll probably get 2 pieces and glued and joint them together with steel joints.
- from glue I read that it's best to use silicon glue. Any recommendation for best glue to join stone to timber?
- Anything other tips/something I missed?

The hairpin legs are from here:
http://ift.tt/1hyOQzq

The desk is something like this :
http://ift.tt/1idvEQE


Thanks guys, really appreciate the help.