the best inexpensive steel baths are by Bette - a German firm. If you can stretch to a heavier gauge of steel then do so - 3.2mm is good, but bear in mind the weight. They're available from builders merchants. Fibre glass baths are not nice, in my view, and I've seen plenty of £10,000 fibre glass jobbies. Steel has an altogether more comforting, more secure feel to it. Your bottom deserves steel.
Basins and w.c.s - check the dimensions carefully. Basins vary from under 50cm wide to well over a metre, but, as a general rule the more ornate 'period' basins are wider, and clumsier looking. If you're stuck for space then the old Ideal Standard Studio range is good, and will never date.
One thing that you really should do if you're changing the sanitaryware is to take the opportunity to take up the floor and check the pipe runs. If you live in an old house the chances are reasonable that some idiot plumber has run pipes through the joists in the wrong location - notching either the top or the bottom rather than drilling a hole through the centre. Those joists should be strengthened.
If, like Patrick, you're getting on in years, consider how you're going to use the bathroom in ten or fifteen years time. Manoeuvring space around the w.c. is important, lever taps are good (there are some stylish ones about), towel rails can double up as support rails if they're securely fixed, that kind of thing. You can always go to Help the Aged for advice. Those grab rails on baths aren't pretty, but none of us, least of all Patrick, are getting younger. Having a different colour wall tile might not be too attractive, but if your sight is failing having spent long hours poring over legal documents.........
Don't go to bathstore.com unless they can assure you that the fittings for the sanitaryware will be available in 15 years time...(or even fifteen months time).
To be honest I detest expensive bathrooms. I've done them from £2000 to £150,000 and the cheaper ones are always the best. Simplicity is all. Getting the tile layout right is the single most important thing. You'll see that Stedlocks has just about hit it spot on, and, for such a small bathroom it really does look unfussed and uncrowded. The rest, or pretty much all of the rest, is rubbish. I'm willing to bet that if I walked into Patrick's bathroom I'd urge him to keep the old stuff, and just spruce it up a bit.
Floor tiles in bathrooms are, in my view, a bad idea. Lino is best, although you should be aware that it fails the slip resistance test, so I'm disclaiming all responsibility. And, finally, does anybody still have one of those bathroom 'sets' which are basically two bits of fluffy rug, one of which is U-shaped, and goes round the 'loo'? I reckon that they're about to be chic again. Rumour has it that Nicky Haslam has one in his bathroom.