Personally I went with an ITX build where I run everything in a Debian KVM/qemu host, including my fedora workstation as a vm with vfio passthrough of a usb controller and the dgpu. It was a lot of fun setting it up, but nothing I’d recommend for someone needing advice for their first homelab.
I feel like that has more to do with the complexity of solving your use-case in software rather than anything to do with the hardware. It’d be just as hard on a pre-built NAS as on a DIY build; though perhaps even worse on the pre-built due to shitty OS software.
Soft wrapping plain-text is surprisingly hard to get right. It’s better to just hard wrap your text when writing an email. Any half-decent text editor/mail client has a feature to automatically hard-wrap a paragraph for you for convenience.