Best Practice - OSPF

[ChrisBS]

Hi All

I'm after some advice on best practice for OSPF.
Currently we have 4 buildings with 2 5406 switches in each that is connected to each other in a ring using LES circuits. This have been setup (not by me) as one area in OSPF (BACKBONE).
Currently we have edge sites connected to cores using on LES. I have attached a picture to show this (With new links)
We want each site to have 2 links from differing core sites which would require OSPF/RIP? What are your ideas for best way of setting this up. All ideas greatly appreciated.

Let me know if you need more information.