Welcome.
I didn't know hairdressers used ladders and tools these days.
There are two main rules in this forum.
You have broken the first one by not showing us pics.
Your doing ok on the second one by asking us for suggestions on how to spend your money.
The tuning box I would definitely do. Search Surrey Rolling Road day for some real life forum member stats on them.
The black grills is a must for any BMW modder with any degree of self respect.
Suspension I can't comment on as it's something I have not fukked with on a car in years.
There are many on here that have gone the ACS/Birds route and many of the many would be happy to help you out in this department.
Wheels are a very personal thing, and personally I would stick with OEM ones as opposed to aftermarket. But this is one of the many things debated on here quite often.
Anyone told you about coding the car yet?