Porcelain is a tough tile which will not crack or break easily. they are very long lasting. vinyl is out dated and just doesn't look good. Your other option should be ceramic tiles. So it should be between ceramic and porcelain. I'd still recommend porcelain but ceramic is cheaper, that's the biggest advantage of ceramic. I bought these porcelain tiles two weeks ago, they look lovely. beautiful hexagon porcelain tiles

https://www.loveskirting.co.uk/flooring-thresholds-c17/by-product-c29/ramp-section-c43/solid-oak-ramp-section-threshold-0-9-metre-p121

We are coming to the end of a house renovation and we had wet UFH installed in all our rooms. It is a bungalow however, it is very unusual property with rooms below the bungalow so it is like a house in some respects. We have a mixture of solid floors and suspended timber floors and couldnt have a screeded system because of the weight. We had an ESP overlay board system installed and have found it to be very effective. Ours is run off an ASHP so I cannot tell you how it would work off gas central heating. Our UFH is on 24/7 controlled by thermostats in each room/area. We did install internal wall insulation on all of the external walls and window reveals and voids beneath the floorboards where possible and my understanding is that this is key to efficient and cost effective UFH.

Rinked, I also considered that, but the table and chairs would block access to the back garden. The front extension would significantly block most of the south-facing light in the living area, the back double doors, are north-facing so they don't bring in any light. So while I agree that you need some sort of entrance into the home, The front extension is a mistake in my opinion. In regards to the comment of keeping the passage, yes it's good to have, however, soo many people who live in terrace houses don't have that option and I don't see that as a significant issue.