Sorry to be late to this, however I also have a history of specifying PC’s for my self and others (both commercial and personal use), so…
1 Avoid systems that rely on the integrated graphics in the Intel CPU’s
(They will actually run Fortnite, but only slowly with low res jerky graphics)
However the Ryzen 3200G & 3400G are good and good value - highly recommended for your use case.
2 Consider 8Gb of RAM to be the minimum
(Windows 10 will sort of run in 4Gb but you’ll get all sorts of problems)
3 If you get an SSD it needs to be at least 450Gb if it’s the only drive or at least 250Gb if you have another drive as well.
(This will probably push you above your budget limit.)
4 Get a decent antivirus / firewall package, Windows 10 Defender isn’t enough on it’s own. This can be a free one, but read the reviews (I personally use Kaspersky, but it isn’t free).
Other than these points, the rest is much less important.
Agreed,
Whilst 8Gb will do 16Gb of ram more desirable
A 250Gb SSD for OS with a second data disc makes Windows work quite well
ESET smart security quite good, have a browse around AV comparitives see what they say
Dont forget that a ‘security’ package is not the only thing to defend your PC/Mac, be aware some of the free ones arent free! I found Avast was harvesting data during testing
Limiting browser scripts with NoScript stops a lot of browser based attacks
Use a Pi-hole DNS, I consider better than an Adblocker - just set your dns servers to 88.198.91.187 & 95.216.181.228 for Ad free internet browsing
Use the MVPS hosts file to resolve a lot of dangerous sites to the root,
Use the add-in cookie auto delete to flush cookies from all but trusted sites
If you must use FaceBook use the add-in Fb Purity which controls some of Fbs nastyness
Mac users - Little Snitch is an absolute gem of a program, an outgoing firewall worth a look
Some of these may seem a bit advanced, just google for a how to.
I use my own Pi-Hole but according to this page https://ahadns.com/ both of those DNS servers are being discontinued on the 28th February 2021. From the same page I assume that 5.2.75.75 (Netherlands) and either 45.67.219.208 (Los Angeles) or 45.79.120.223 (India) are the replacements.