Both Hansgrohe and (Friedrich) Grohe are German companies; Friedrich was a son of Hans who went on his own in the 1930s, so they share a certain heritage. These days, Grohe is larger and no longer family owned. Both produce outside Germany as well as on their original German sites still. Both produce "basic" and "high-end" ranges. They're both regarded well back home in Germany, much of the choice is down to personal preference. Hansgrohe is on average slightly more expensive (but not on everything). They also own the Axor design brand which has a more "ecletic" selection. One can mix-and-match; in our bath (bit messy, sorry - we're using it for the washing up while waiting for the kitchen to be installed), the mixer is Grohe as is the shower wall outlet, the shower rail and head shower arm (just above the shower screen) are Hansgrohe pieces. At least the chromed finishes are very close for the two: Both can be sourced well below retail list prices - if you're prepared to wait, German online sellers for bathroom goods tend to have many-months delivery timelines. For Grohe essentials (the classical Grotherm mixers) at least, any German DIY shop stocks these at very attractive prices (the difference to the UK retail price list will pay for the ferry ticket and fuel).

I would move the basin back to the wall opposite the wc. The benefit being you won’t be stood under a beam, it’s a wider space allowing a better mirror and storage. Plus it frees up some wall space near the shower for a towel rail.

With extension (laundry area opposite bathroom)

I don’t know how Jonathan does it. He’s some kind of spacial genius.