what's the budget?

you'll want two sinks, no? a vanity that long will need to be custom made.

you could do two 48" vanities and do a drop down countertop for a makeup spot in the middle.

something like this

If you don't need that, then find a longer vanity or do something like these

if you don't want white, pick a darker tone from the tile, or even a wood vanity like this floating one below, (if you want sconces, you'll have to get the wall wired for them. not a big deal, you'll just need to know where the sinks and mirror are placed)

go to a tile store and find a nice porcelain tile that matches you show tile. take extra tile w/you if you have it.

I'd do white vanities if you want to brighten up the space. you could find a nice granite or quartz countertop that works w/your tile.

sand and prime the linen cabinet and use BM Advance paint. do a contrasting color. new hardware.

get two lighting fixtures for over each sink.

Beth, thank you! You're AMAZING! Love all your inspiration pics and this was so helpful.