Spreading one virtual location over 2 physical with own WAN

[whatever]

Hi @all,

I'm searching for a solution for the following setup:

LOCATION 1
WAN1 <-> pfSense1 <-> some VLANs
                      |
                      | Layer 2 Link (slow)
                      |
WAN2 <-> pfSense2 <-> same VLANs as LOC 1 
LOCATION 2

I want to control (based on Location) which client uses which WAN to prevent tracks like this:

client (LOC2) <-> GW pfSense1 <-> WAN2

which would overload the layer 2 link between the two locations. The locations are connected with a layer 2 directed WLan Bridge and the Bandwith is limited. But I want clients in both locations be in the same layer 3 Subnet…

But if one WAN connection fails it would be nice to have failover nevertheless...  :P

Is this possible?

EDIT
To be more precise:
I want to route outgoing connections in location 2 through WAN2, outgoing connections in location 1 through WAN1. It would be easy to put the clients in dedicated location dependent subnets. Then I could use a more or less standard setup. But the clients in both locations have to be in the same subnet...

But if the manager wants to cross the street between the two locations without loosing the WLAN connection on his laptop (the roaming part in the WLAN has been successfully implemented) then it goes difficult...

Regards
w