Why routers and not proper wireless access points and wireless repeaters? I'd look at Amped units if you want longer range. You can also look at powerline repeaters. The older versions of the RV082, or at least with older firmware, sometimes had poor throughput with the firewall enabled, test the internet speeds and verify that they are close to advertised speeds, update the firmware to latest version as well otherwise replace it with a new unit. I assume they don't use the dual WAN feature or VPN.
Amped: http://www.ampedwireless.com/
Amped: http://www.ampedwireless.com/