If performance is the goal, do not pick a M.2 SATA SSD; it will give approximately the same roughly 500MB/s max performance that you get from a simple SATA 2.5" SSD. It's just the same as the 2.5" SSDs, but packaged as a M.2 stick. SATA III / SATA 6G is 6Gbits/s, not 6GBytes/s; and has a 8 in 10 encoding, so is theoretically about 600MBytes/s (but that works out around 500Mbytes in practice).
It looks like the FX503 is a 2017 machine with an Intel 7000 series CPU, HM175 chipset, and PCIe 3.0. 2TB (either PCIe or SATA) should be no problem on Windows 10/11.
Get a PCIe 3.0 NVMe drive if you want the best performance. PCIe 3.0 is essentially old/obsolete now, but that's the fastest your machine supports; but you can install a PCIe 4.0 drive and it will just be limited to 3.0 speed. They can go up to about 3000MBytes/s. For higher end (gamer performance grade), something like a Seagate Firecuda 510, or a WD_BLACK SN750 (those are PCIe Gen 3 / 3.0 drives); but even a general consumer grade Seagate Barracuda 510 or Q5, or a WD_BLUE SN550 should significantly outperform the best of SATA. M.2 SATA kinda made some sense back in 2017, but really should be avoided in 2022 (unless money is extremely tight or you have a SATA-only (B-key) M.2 slot).
