For Base-T networking, you have to use Cat6a or Cat7 cables. The main difference between them is the distance (up to 55m in Cat6a and 100m in Cat7). However, as already mentioned, SFP+ is much better in case of bandwidth, stability, and latency.
From year to year (since S2D was released in GA) I've tried to configure it for 2 nodes and it always fails. The stability of work is very poor, the failures to tolerate is quite low and of course, the storage spaces itself. Never ever use the parity SS with HDD. Also, it's very painful to restore the storage spaces direct (and storage spaces) if one of the disks fails (you have to deal with not well-done PowerShell commands).
If you are looking to cluster 2 Hyper-V servers, take a look at other SDS solutions such as Starwind vSAN or HPE StoreVirtual. They are much stable in 2 nodes switchless configuration with convenient GUI (supports both storage spaces and hardware RAID)