Options for redundant connections between M4100 and M6100

I've inherited a network that's currently 1 large broadcast domain with approximately 2000 clients. I'm working with a fiber backbone and have 40x M4100 lagged to an M6100 with 2x XCM8944F blades. My initial goal is to segment the devices using VLANs and subnets and am leaning toward a ROAS configuration. The network is currently using RIP and I would like to move over to OSPF in the near future. I've been weighing the differences between using VRRP, OSPF, and LAG connections for redundancy throughout my network and am hoping to get some feedback on what the community thinks of using these technologies with my topology.