Can i ask you, using VRRP is good, one master one back up, but can VRRP change the way if master fall over? (means router is active but gateway is down),
In VRRP when master fail, backup get active role. Of course you need redundat ISP connection. In "on master" and "on backup" you can enable or disable ISP interface.
You have 3 seconds aprox (in my case) down to backup detected a master has down, but this time pass all work without problem. When master go up backup wait.
You can use 2 ISP without problem, but vrrp it's for router hight availability, if You like change ISP or gateway no need vrrp You can check with scripting ISP1 ping and change default gw to ISP2 when ISP1 fácil.