I assume the router part is a must-have? Gigabit switches with 10Gbps can be had relatively reasonably (Woven/Fortinet LB4/TRX100, for example), but adding router functionality really ups the cost. How many gigabit ports do you need? Could you do an x86 router with 10Gbps as uplink and then a couple multiport gigabit cards on the LAN side?