I feel your frustration, as I too, find many items that I would love to use in my renovations that are from the US and can not find here in the UK. That's where I find knowing a good joiner or carpenter comes in handy. All the best.

Hi. Do you have a picture of the vanity? I would have the mirrors as wide or a bit wider than the sinks . Do you also have any wall space either side of the vanity?

Sorry - only just seen this ! Needs a site survey, by someone with plumbing knowledge, I agree - and then a good bit of planning to get all of your boxes ticked. Most high end en-suites that I’m involved with the design of have a separate built in loo and basin ( with extractor fan) . Then a shower area ( with another extractor fan ) , bath and big vanity with storage with shaver /tooth brush sockets . If it’s a really big room then an area away from the water areas for hairdryer and makeup etc although this often gets incorporated into a dressing room area that’s often next to en-suite .

Right...change of plan...decided to get a Chippy to make the actual drawer unit out of MFC in a dark wood effect. As previously suggested by Daisy (thank you). I give up trying to find something off the shelf! Still having a problem finding a basin with 2 tap holes though (reason is it needs 2 x sensor taps - one hot one cold) So my question should be - where can I find a basin suitable for a vanity drawer, with 2 tap holes! 800w! Thank you