Convertible or notebook + tablet for studying?

My brother needs a NoteBook and since I would really like to buy a tablet for the notes soon, I'm considering buying a convertible and giving him my ThinkPad (which I find very good by the way). The problem is that I don't know which one to buy and I don't want to spend more than 800 euro on it.
I don't do anything great with it. Notes in the lecture and I sometimes open several apps / programs / tabs at the same time.

I also don't want it to be too small (14 inches would be perfect) or too loud.
I have written down some Conertible products and am considering which I might buy.

Which convertible would you recommend? Would you recommend a convertible at all? Or keep ThinkPad and get a tablet? What are your experiences

I wrote that down.

notebook:

- ThinkPad

with touch:

- Microsoft Surface

- Acer Switch 3

- HP ENVY x360 15-ds0101ng

- Lenovo Yoga

- HP ProBook

- Acer Spin

All of the devices mentioned are represented at my university.

I really like the Lenovo Think Pad. The thing is really solid and you can just hide the pen in the housing and charge it.

But I have a ThinkPad E480. Only he has no touch.

You probably have a ThinPad Yod right? I was discouraged from IdeaPad.

https://www.lenovo.com/...MD00000384

Why in CHF? Doesn't the site also have euro?

Simply google the model. You will then be shown pages with EUR