Glad you got yourself up and running.
Before you get too far down your current path, you might want consider just bypassing the whole "bridging NICS to simulate an internal switch" approach and just get a small switch.
They're cheap (<$30) and will definitely perform better than multiple NICs.
Save yourself grief in the future, plus you can keep those extra internal NIC's for the scenario(s) you may find later (want a "guest" only WiFI?, need to add some isolated machines? etc.)
Just my $.02, but you'll find this general opinion echoed alllllll over the forums 8)