From a design perspective, one key rule is to keep it as simple as possible. You do not want to introduce complexity in your environment. I am assuming this is only a small environment (from the license the you have and from the number of networks, not using VLANs). Is the 1GB network being saturated already? My approach in this is to identify where the bottleneck might be. Majority of the issue with vSphere performance is in storage, not in the network. If you are really worried on the network scalability, the easiest approach for me is to enable VLANs and allow trunking. You can then combine the 4 NICs in one vSwitch and let the default load balancing policy (route based on port ID) do its thing.
Just my 2 cents....