I know in Windows with SMB multilink, you can max out dual 10Gbe connections without LACP. Depends what you're putting on the ESXi, you could LACP them, or assign 2 virtual adapters to each VM. I have a dual port 10G card in a thunderbolt enclosure I max out commonly on my laptop. Moving to 40Gb now and we'll see how well the thunderbolt link keeps up. I know for a fact that it won't be able to utilize 80G
Definitely look into SR-IOV.
I really want to play with some remote RAM caching my server since half of the 512G sits unused most of the time.