I am setting up a couple of new links to a remote office and would like to use OSPF for dynamic routing. The primary link will be a 2MB Mpls link and the secondary will be a GRE vpn tunnel over the internet. I am still in the planning/design phase and I am wondering about the best choice and best practice in terms of assigning the router-id's as I understand this will dictate which router will become the DR. I am looking for a suggestion on whether or not I should use a loopback address or just manually configure the router-id? Also, what IP addressing is the safest to use for router-id scheme and also what would be the best router to choose as the DR assuming all the routers are the same in terms of processing power and memory?