"The reason I am exploring this approach is due to a specific scenario at work where we need to establish redundancy. While we could achieve this through a router link, we are currently limited by the number of available ports on the router."
Yup, routers are often port limited, but for routing redundancy, a pair is often considered sufficient. The pair could be two routers, two L3 switches, two stacked L3 switches, L3 switch and a router, etc.
As you now note you're trying to solve a real world redundancy problem, I would suggest you create a new posting describing it. Your lab might not lead to an optimal solution or even have real world pitfalls.
For example, @MHM Cisco World mentioned you need an IGP, but if each router in the posted topology has an interface in all networks, they don't need to cooperate with other routers. But, for hosts to get to other networks, they generally should have a defined gateway, and if they do, for redundancy, that's often provided by a FHRP.
As another example, @MHM Cisco World has you needing PVST root placement. Very much NOT needed in a lab unless it's something being examined. In real world, it could be a very important consideration, but there's much that can go into selecting root placements and interactions with other network considerations, such as the root switch is normally the gateway too.
There can be a huge difference, in real world networks, between a network that functions correctly and one that also does so well! Also, laugh/sigh, there can be a huge difference in how a network might be ideally designed, technically, vs. real world budget restrictions.
On these forums, you'll likely obtain good responses to lab or real world issues, but don't assume answers to the former are always directly applicable to the latter.
