We had extensive work done on our place not long after we moved in, over 10 years ago. The kitchen was knocked through into the old bathroom, and the new bathroom installed in the next room along. It was great to be able to create the new bathroom from scratch, gives you a lot of freedom.
We got our fittings from Bathstore and the builders installed them. Only problem was the chap who did the job was actually a carpenter, not a plumber, and he made various cock-ups, so we subsequently had to get the local bathroom specialists in to do the job properly. That said, the bespoke fitted cabinets are excellent, so the carpentry skills didn't go entirely to waste.
A toilet, that isn't 'floating', isn't square, doesn't have any poxy buttons to get jammed and has a decent enough flush to get rid of the occasional big log. No jobbie inspection platform required.
Our toilet is 'floating' with a concealed cistern - at my wife's insistence. Her reasoning being ease of cleaning. I was dubious about it at first but it has been fine. No plumbing problems at all. However, the cistern was one of the jobs that was cocked up and had to be redone, which involved the cabinet being extended upwards. The new cistern has a Geberit flush mechanism, which has performed reliably for something like 10 years now. Highly recommended.
Our current one has a sliding door, the track of which is just great for collecting grot. Not sure if we have enough room for a pivot door though, will have to measure.
We ended up with a bi-fold shower door - the make is Kudos. Again, seems to be very reliable and sturdy. it folds very neatly to allow entry/exit in limited space (shower is next to bathroom door) and can be incorporated into panels as wide as you like. The shower isn't totally enclosed, so ventilation isn't a problem.
A shower, thermostatic mixer is a must. Am ambivalent about having a rainfall head or not, there will be a head on a flexible hose whatever happens.
Ours is a Hudson-Reed thermostatic mixer connected to the mains, with a dual output with a 'rainfall' head and secondary head on a flexible hose. The original mixer tap failed after a few years, can't remember why, but I replaced the inner workings - got the parts direct from Hudson-Reed - and it has been fine ever since.
We're lucky in that we have a combi boiler and the shower is quite close to where the water main enters the house, so we have excellent pressure and an unlimited supply of hot water. We stayed at my brother's over Christmas and he was raving about his new shower but it's a desultory dribble compared to ours.
A decent hand basin. Something that you can use for more than just rinsing the tips of your fingers. Probably one which sits on the top. A good under sink cabinet. None of this floating nonsense again, that's just wasted space to collect cat hair and other grollies IMO.
Ours is built into the top of a cabinet. While I largely agree with you about wasted space, the only problem with not having that space under the sink is you have to stand slightly further away from it - unless you have stumpy feet.