Self-hosting

Please forgive the annoying asking for info post

I have 100Gb of stuff on Google drive and I want to move it in house, I guess via Nextcloud? At the same time I want to try things like self hosting Notesnook and a few other things like ad blocking the home network etc

I was going to try starting with a raspberry pi 5 with 8Gb of ram and an SSD and some form of Linux obvs but in my limited reading I've seen that's very not recommended for Nextcloud.

Key things are low power usage/quiet, I'm not THAT fussed about download speed to other devices but keen to avoid as much lock in as possible. Budget around £200-300 to start with.

I've seen recommendations for thin clients, kinda like the idea of a NUC but they're pricy for the form factor. Having it be small would be a plus but I do have an old windows 8 machine from 2013 in the cupboard in an ATX case but the power supply draw feels like it would be excessive

Hints appreciated or tell me which community to go check, thanks in advance

EDIT: Thanks for all the hints!