Local Paintshed can get CooVar or Johnstone's single pack.
It's our main entrance and needs to be really grippy as it's 6 steps and gets ice/snow on it regularly... I will grit it, so needs to be resistant to salt.
Is it painted already? We've got a concrete set of steps into our house which were painted just before we moved in. The paint came off through use, we re-painted and it came off again. Something about concrete steps holding moisture which can then come out and take the paint with it. When I look at the neighbours, none of their steps are painted, so I've just stripped back to the concrete and I'm going to leave them.
It's concrete, no paint.
We've just had the pre-cast steps repaired and all the pointing done on the brickwork.
Do you need to paint it? I'd not if I could get away with it.
Otherwise this is a bit like a what bike for £1000 question.
Performance will be much the same across brands if you are comparing like with like (technology wise e.g. epoxy 2k or 1k acrylic). So what ever is available to you decide how much you want to spend as if a brand offers a range then the more expensive option will generally be better with diminishing returns.
I'd be less concerned about the paint and more about the prep. Follow the manufacturers instructions. If the steps are precast and old then you may need to consider how you clean them and if they need a sealer/primer. If there is lots of green (Fresh) concrete check your paint is suitable. Generally water based is better for green concrete if I remember.
Crumbling 1970's concrete, filthy of course, with fresh repairs.