Canon EOS model and lens(es) for rock climbing photography?

That's easy. Get an SL2 or SL3. Or maybe an M6 Mark II for its irresistable Pre-Shooting.

Small, light, simple, inexpensive in case you drop it, quite durable, and quite excellent. It's really important that it be simple so you don't miss shots for stupid reasons, such as you can't take 10 minutes to figure out the camera. The trio of lenses covers 10-18, 18-55, and 55-250mm, and they're small, light, inexpensive, and quite good (not perfect, but small, light, and good enough for what you need). You need the EF-S 18-55 and 55-250 IS STM I would think, or maybe one big heavy zoom like 18-135 or 18-150 or something. Unfortunately, Canon has discontinued the 10-18 and the 55-250, but they can still be bought.

Not very sophisticated focusing, but flexible powerful focusing tends to be either (1) big, heavy, expensive or (2) complicated -- I think.

The other one to consider is the M6 Mark II. It has all that, but smaller, lighter lenses, and it has an irresistable feature: Raw Burst with Pre-Shooting. That means you can photograph up to 1/2 second before you pressed the shutter fully (great for falls). Reviewers find it easy to use. The bad news: I find it hard to use in all but the simplest modes. Maybe easier after I have spent several days studying it and setting it up.

M50 Mark II is good, and much cheaper than M6 Mark II, but I don't know if it has Pre-Shooting.