A few years ago I replaced all of the toilets in my house simply because they were blue and 40 years old and just kinda crappy.

I live in America and I use a rubber seal since if you need to remove and reposition the toilet you can reuse the rubber seal instead of having to clean potentially poop and other bacteria laden wax out of a hole and replace it with another wax donut.

The waxed donuts were three to five dollars a piece and the rubber seals were ten.