U-POL sounds good to me.
I used their products many years ago, and never had any issues with the quality, and the prices were OK.
The best etch primer I ever used was called "Guard Etch Primer" apparently, my father used to liberate small quantities of it from where he worked.
It was evil grey/pink stuff, not twin pack, but it had a special thinners.
It probably had its own dedicated COSHH regs too, but I was ignorant of such things in my youth
Dried to a rock hard finish and never ever rusted even when damaged.
Probably been withdrawn on H&S grounds by now though..............................................................