Re: 2 ISP - VOICE IP & DATA - COMPUTER CONNECTED TO PHONE IP - BOTH THROUGH 2 ISP DIFFEREN
Although it doesn't matter what source IP voice & data packets have since you seem to already know the voip server IP(s), why would you need to put your computers behind the phone sharing the same 1G or 100M cable while you have a good looking switch with enough ports? You just need to pull another cable(s) to the computers. It makes the switch and FG30E difficult to handle QoS on the LAN side efficiently.
For the question, you just need to have a static route for the voip server IP(s) toward WAN1, while the default static route is going toward WAN2. If you want to let them failover each other in case the circuit problem, you need to set a set of lower priority static routes to the opposite side then set link-monitor and let those high priority static routes to go away.