Best scanning setup for $5000 CAD?

Welcome to the forum @shoochyu

A good copy stand is astonishingly expensive if bought new. Prices on ebay are lower, but still look expensive if you think that they are “just a board with a column”. Second hand enlargers can be quite stable, but are not always ready for camera attachment.

Something like a Nikon ES-2 has its strengths e.g. in stability and blocking stray light, but getting a device that accommodates 120 film seems difficult. Please note that scanning square 120 negatives either wastes a lot of pixels or requires stitching.

As for camera and lens combos, have a look at sigma’s fp-l with a sigma “Art” macro lens. One of the best price per pixel values as far as full frame cameras go. Cameras with smaller sensors (APS-C or even micro 4/3) could be an alternative. For scanning purposes, you don’t need an electronic viewfinder. Something like a Sony A6xxx might be quite usable for reasonable cost. Again, check out Sigma “Art” macro lenses, they seem to perform well according to Lens Tests — Close-up Photography

Most of all, checkout
Let's see your DSLR film scanning setup! - #2 by Pbranly and
Suggested backlight sources for scanning film with DSLR - #2 by nate
etc. Read, collect info and opinions about proposed gear and build your own idea about your future rig. Then, come back with specific questions. You’ll learn more this way than with handing out your cash in the expectation that someone can match your requirements with a proposal.

As for your budget, it should be good enough for a decent rig.
If you’re into DiY, it should be plenty.