Work, general surfing and a little gaming (enough to need a PCI-E slot).
Perhaps DDR5, not so much for the speed but for the error correction (except I see it is not exactly mainstream)
There's no DDR5 out there yet. So that will have to be sacrificed. It won't be released at minimum until Alder Lake and Zen 4. If ECC is really needed (although your use case doesn't seem to necessitate it), your only choice is to buy some cheap HEDT platform. AM4 has sketchy ECC support, but to make it function for real, it's not really possible. For anything else, here's a part list of what you can buy and approximate current prices:
i3 10100F/i3 10105F - 100-110 USD (Decent chip for budget, comes with cooler)
MSI B460M Pro-VDH Wi-Fi - 85-90 USD
GTX 1650 Super - 450-470 USD (I know, this is painful, but if your GT 1030 is good enough for you in games, I would recommend to stick with it. There are odd used deals, if you are thrifty. F Intel chips don't have IGP, so be warned)
960 GB SATA SSD - 90-110 USD (Try to find something with at least TLC flash and preferably with RAM cache. If there's no RAM cache, then at least TLC.)
Fractal Design Focus G - 50 USD (Anything works, but this one is rather cheap, seemingly decent quality and has two fans)
2666MHz DDR4 JEDEC RAM - 60-65 USD (Comet Lake chips have locked RAM support on non Z boards, i3 only supports 2666MHz JEDEC speed, XMP is likely not supported, there are no hacks to avoid this limitation, you can only buy Z board or increase budget and get B560 board)
Enermax RevoBron 500 - 65-70 USD
Total cost without graphics card: 450-495 USD
Total cost with graphics card: 900-920 USD
BTW my prices are from Newegg, so you may find some better deals. You most likely can find a decent PSU for 10-20 USD less elsewhere.