Nyxeris, would my suggestion be worth ago, potentially cheaper if it has to be smuggled past his Mrs!? (but make sure pixels are ok!)
A pro head unit is only part of the puzzle sadly.
Ze Germans love their options lists, and all the in-car entertainment stuff on our cars was a good example. You could choose between business or pro stereos, or business or pro nav. Then you had to choose if you wanted no Bluetooth, BT calling, or BT calling and streaming. Then you had to decide if you wanted the USB/iPod interface, and if you wanted the base, hifi or Logic7 speaker setups. All of these were cost options that had to be ticked individually, and they weren't cheap either.
It's possible to retrofit it all, but all the kits/wiring harnesses were discontinued years ago, and breakers are charging a fortune for the parts. So even if you buy the pro unit, unless the car already had Bluetooth (which it sounds like OP's doesn't), you're still missing all the other parts needed to get it
If I need to up the budget so be it (no missus to worry about lol - long story)
We've all been there lol!
If you're happy to spend more, there are fully integrated Chinese Android units that are lightyears ahead of the factory stuff. They do have small annoyances like mine not knowing its lefts from rights, but all in all they're good little units. Pics etc. in my thread here.
Out of interest did you buy a genuine BMW clutch or one from Valeo/Luk etc? Clutch kit and DMF were LuK, all bolts/fixings etc. genuine BMW via Cotswold. The indie that I use for Landy stuff swears by LuK which is good enough for me! The Valeo parts would have been slightly cheaper but didn't...
www.babybmw.net
You're looking at £300-350, but they're modern kit that's fully integrated into the controls/CANbus, and they're relatively easy to install (and uninstall and stick on eBay when you sell the car). You'd have to spend a good £1-2000 to get anywhere close to the same functionality retrofitting factory parts, and that would be a major wiring/coding job, not 30mins with a screwdriver.