|"I believe trunking (splitting one larger connection into several smaller parallel connections) "|
Sorry its just the opposite. Trunking is where you have one or more connections between switches that are dedicated to switch to switch communication [which is what you were asking for].
Might want to review this
For example you can have two gig wired connections between the switches and by "trunking" them you can get a combined thruput of 4000mbps [full duplex gig is 2gig which doubled is 4gig]
In your case it would appear only one wire would be required between switches.
I would suggest not limiting your thought for transfer rate to that of the router. I have to assume you want pc to pc communication also. Gig is the standard in todays networing hence the suggestion.