Ya we have two isolated switches & networks for the iSCSI traffic.
Your ESXi hosts can have only a single Software Initiator, but you need to create two separate virtual networks (unless your splitting things up with VLANS).
Here is a screen shot from vCenter.
2 separate virtual switches (note that I setup the vSwitch's for local vm iSCSI traffic too)
Here is a rough logical wiring diagram I made up for our networks way back.
Let me know if you have any other questions.