Its whas bad images, so i will try to explain.

After our provider whe have a RB1000 gateway that then go to a Mysql-DNS server
and to rb600 to send the signal over to site 2 and 3 and client anntenna to send to som clients in that area.
On site 2 is our office is here we have place to have servers so on here.
On site 1 whe have limitd spece to work on.
So ide was to use site 2 as main place to send out to the other sites.
Site 2 we also have 2 AP and we sending signal over to site 3 and 4.
On site 3 its a powerful intel dual core server that sending over to site 4 and 1, and 3 ap and a rb 600 whit 1 ap.
on site 4 we have 1 ap and we are seding to site 2.

So this will make a circle between sites, the reson for this is to make fail over and loadbalance system.
So my quest is, of cource i can just brigde and make it easay. but this size network i have never done.
So where to start? Is many ways to do this but what is best?
Have read about Mesh setup, mpls so one.
Do not nesesery have to tell me everythink but just som links, or whats will not work so on.
Have C-subnet, so my ide was to set up PPP Authentication whit mysql. to have control over clients our is it a other whay?
How will you have done it?