@DarlingCoffee I would have recommended Drench, they were fab last year for our upstairs shower room but have been a bit of a headache this time around with regards to delivery!
That said, they did manage to get a replacement bath to me within a few days, & exchanged the incorrect valves they'd sent within 24 hours. When I changed my mind on the shower tray last year, they were also quick and helpful with the exchange. I wouldn't disregard them, just order early and double check everything before you start installing, just in case.
The main thing I think is to choose good quality makes especially for things like taps and showers. I got Hudson Reed stuff for upstairs - decent quality for the price but I have a few niggles (a decorative part coming lose, bracket that holds second shower head keeps sliding down) so have gone for Crosswater stuff downstairs.
Worth looking at recommendations by Piglet John on the Property & DIY forum. I have a surface mounted mixer upstairs rather than one buried in the wall on their recommendation, for example, as they said its much easier to fix if something goes wrong without smashing up your tiles!
Look at guarantees too - I went for a Roper Rhodes vanity over a very similar looking one. £160 more but a 10 year guarantee on the unit & 20 years on the basin, rather than 2 years on the cheaper model, which hopefully reflects the quality of the product. I was surprised how much the guaranteed lengths vary.