Are these the final spec for RAM, if so It depend on what you use your Desktop for, My next build will be similar graphics wise and SSD size as I wouldn’t need more graphics power than that, and I have 2 x external 4Gb HDD’s for my main storage. I will probably be going AMD though for graphics, as I believe driver support in Linux is a lot better at the moment. The 300W PSU seems a little low for upgrade potential in the future, you may want to consider at least a silver or Gold 500W PSU to give you better upgrade potential particularly if you plan to upgrade the Graphics card to a more powerful one at a later date. Obviously this would be more expensive so if costs an issue and you know you can manage on 300W then look for a value Silver/Gold model that fits your budget. Same goes for Ram, If your budget and the PC will support it I would aim for as much as possible. I currently have 24Gb in my Desktop and on my main Laptops have 16Gb as I play with VM’s and it gives a good deal of head room for running them with a decent amount of virtual RAM.
If the laptop and All in One are backups and not used much for RAM intensive tasks then 8Gb should be ample otherwise budget allowing, I’d aim for 16Gb.
As I don’t know your personal use case for the PC’s this is just a personal view of what I might consider in your shoes.
PS stickers are a personal thing, I have one laptop covered in them, others are pristine.