OP, my comments on the two printers you linked to. (Canon and Brother).
1. I see you have abandoned getting colour printing. This can work fine if you can use some local service for infrequent colour prints.
2. Both printers can be connected to one computer via a USB2 cable. (At least one says not to use a USB Hub for this.) IF you have a local network in use, it is possible to make the printer available to others through the only one connected to that printer as long as that one computer is running. HOWEVER, it is much smoother to have the printer connected directly to the network so that all computers in the network have access to it directly. This can be done only with the Brother printer because it has also both a wired network cable port and built-in 2-band WiFi for cable-free connection. (My Bother is connected this way to our home network because its location makes a cable connection harder.)
3. It appears the native resolution of the Canon is 300 dpi but you can get 600 dpi (by simulation, I think) from it. The Brother has native resolution of 600 dpi, or MAYBE 1200 - not clear from their specs.
4. Both recommend you use genuine toner carts made by the printer maker. For the Brother I am sure you can find on the internet a way to manually reset the printer to recognize a new cart, even one from a third party, so it will work. (This is NOT the same as a complete "factory reset" of the printer that changes all of its settings.) I do not know whether this can be done with the Canon, but I doubt it.
4. The Brother includes an automatic document feeder for the top scanner which you may not use often. However, you do NOT have to use it - normally you can lift it to insert a single sheet if you wish or to custom-position one sheet.
5. If you are working with a heavy stiff sheet of paper (or sometimes a sheet of labels) using the custom feed tray at the front, the Brother allows you to open a rear panel and let the printed sheet exit straight out the back.
6. The Brother can do double-sided printing automatically'; the Canon does not appear to do this.
Relevant to any printer: in ordering replacement toner carts, compare prices and claimed page yields. Most of the the high-yield carts are better per page, and for this (laser type) you do not need to worry about clogging on a cart used less frequently. You may not get exactly the page count they suggest per cart, but the high-yield ones DO give you a much higher yield. Sometimes buying on sale even when you do not need it yet is a good deal.
For the Brother unit, you can get a VERY complete Manual to be downloaded to your computer as a .pdf document by searching for "dcp-l2640dw toner manual" on the internet. It should get you to here
From that use the little "save" icon at upper right to set where it should put that doc on your computer.