Going the Proxmox route provides options as you can run UNRAID, TrueNAS, and everything else short and long term in separate VMs. UNRAID and TrueNAS are primarily digital storage appliances with ability to run VMs, whereas Proxmox has been architected to reliably run and scale VMs of any kind.
However, you should test if the T630 is capable of efficiently running all the workloads you require under Proxmox/UNRAID/TrueNAS. You need to test yourself for a bit of time prior to going one way or another.
A T630 is very well suited to run with HAOS and I also tried once, just briefly as a ‘is this possible’ test, to install Proxmox on it and it worked.
However, with Proxmox and the services you are mentioning might be another ballgame and unless you find someone who is doing something similar, your best option would be to just give it a try.
Also, I would advice to run it with at least 16Gb RAM.