This is a fairly straight forward dual wan setup and vlans for all the LAN subnets using one bridge.
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1
The most important thing is to detail your requirements accurately.
a. identify all devices/users ( internal, external and admin )
b. identify all the traffic they should be able to accomplish.
Detail the WAN requirements…
Single WAN, with failover to a secondary WAN.
Both WANS shared by all users… ( what happens when one wan fails )
One WAN only for some users and the other only for the rest ( what happens when either wan fails )
- any port forwarding required
- any vpn required aka wireguard
- is WAN1 a public IP, and if so dynamic or static.
- is WAN1 a public IP, and if so dynamic or static.