You can even create a QOS Policy in which it will prioritize the traffic you choose ;
Plus you would have the option to control what kind of web traffic is allowed/restricted via CSM
I can provide you with proper screen shots to setup firewall filters/csm and allow/restrict sites on your entire network,
I would suggest the draytek model of 2950 (as it supports 250+ VPN Sessions as well), more throughput then 2820 and have two Ethernet wan ports, so your cable broadband would terminate directly into it and you may need a cheap adsl modem to connect your adsl it to its other wan port
hope that helps