Choosing 10gbit NIC for 3 OS's

I'm upgrading my homelab from 1gbit to 10gbit.

I need help to choose a 2x10gbit NIC for

1. FreeNAS 11.2
2. Vmware ESXI 6.7
3. Windows 10 v1809

I've already chosen the 10gbit switch as Ubiquiti US-16-XG, which support 12x10Gbit SFP+ ports.

I've narrowed down to 5 options (all supporting 3 OS's above):

1. Intel X520-DA2
   1. Lifetime warranty
   2. No support for RDMA
   3. $415cad
2. Mellanox Connectx-3 Pro (MCX312B-XCCT)
   1. 1 year warranty, I believe
   2. supports RDMA
   3. $300cad
3. Addon Chelsio T520-CR-AO
   1. Lifetime warranty
   2. supports RDMA
   3. $320cad
4. Chelsio T520-CR
   1. 3 year warranty, I believe
   2. supports RDMA
   3. $483cad
5. Chelsio T520-SO-CR
   1. 3 year warranty, I believe
   2. supports RDMA
   3. $277cad

Yes, Im in Canada.

I'm not considering:

1. Chelsio T420-CR
   1. No support for Vmware ESXI 6.7 (latest supported is 5.1)
   2. Price will be the same as T520 for me, which has a newer generation ASIC
2. Intel X710-DA4
   1. No support for Windows 10
3. Intel X710-DA2
   1. No support for Windows 10

A couple of questions:

1. I've heard that RDMA is much faster than non-RDMA NIC like Intel X520-DA2. Is that true? If that's true, then I guess Intel NIC is out of the question.
2. What's the difference between Addon Chelsio NIC and Chelsio NIC?
3. What's better T520-SO-CR and T520-CR? I've read the discussion and I think the T520-SO-CR is a better value.

Anyway, what should I choose?