yes it is possible but only when u telnet it otherwise u need roolover cable
well, it depends on what device will you connect your router, for example, router to router/ router to workstation, crossover will do. but if you connect it in a switch, straight through cable is necessary.
If your router has auto MDI-MDIX feature, any other device will fit on whatever cable tou use but for best practice, use the appropriate cable in connecting devices. same device – crossover / different device – straight through.
Although the best cabling type for like devices IS a crossover, the routers you mentioned would probably work better being connected via LAN switch, or some type of WAN link…