Chuck - Congrats! You and I feel the same. BMW peaked with the S62, S54, S85, and S65. Get off my lawn.
There are some cheaper options out there for the stock springs like the DA konis from TCKline, you don't have to go full retard like I did.
That's correct, I'm using their ET35 9.5" MT-1. For some reason they don't list it as an option anymore for the E9x, probably because it requires a spacer to fit properly and their 10" wheel doesn't. I'm using a 12.5mm spacer in the rear (for an effective 22.5mm offset, .5mm furhter out from stock) and a 15mm with the ET45 front (for an effective offset of 30mm, 1mm inset from stock) with their 8.5" and 9.5" MT1. I can't speak to the MT1-R but I really like the MT1, it's the best bang for the buck out there IMO.
The ABS doesn't care about the tires sizes much and seems to work really well no matter what weird combo I have on the car. DSC is a different story as it can get much more sensitive without the factory rolling diameter stagger, but there's a button next to the shifter that makes it irrelevant in about 1 second. For street tires you might look at the 265/35 and 285/35 Hankook RS3