I picked DIY with regrets but it does not tell the full story, I guess I now need convenience for my own productivity. For me the cons outweigh the pro's of a diy system now I have spare money to invest in my lab. When I was broke it was great!
The con's are scraping a system together and spending precious hours over multiple days configuring it and then maintaining old kit, I am not a storage guy. Every configuration took a lot of time to research and then failures and restarting from scratch and then poor performance that needed investigating.
When I bought a Qnap solution, I was up and running in less than hour including adding the discs.
I have a Rutx12 router that has 2 cellular modems, if the WAN link fails it will route via 2 load balanced 4g connections. It works great in my hack rack and means my lab is completely mobile with no breaks in connectivity
Sounds like you need to run a hypervisor and then you can pick and choose plus test different options. You can then create templates and clones that will save you so much time time. Proxmox or ESXi will get you going.