ok in need some help i am starting to work on my bmw and i would like some help on where exactly to start and where to get some high quality parts and all what i would need

First is the differential ratio.

You have a 2.79 to 1 ratio.

Putting in a 3.42 to 1 is the best change for the $200 dollars it will cost.

Next is a change of ECU to a later version of the 027 ECU that has a chip that is not soldered in. Adding a chip on an ETA provides the biggest percentage change in ANY, car chipped.

Around a 20% jump in torque and horse power.

That should provide you a good starting point.

Later,

528e is not a good racer. the cam is cast not forged and cannot handle the RPM's. cheaper to find a 535. but if you really want to...
you will need 325i heads, cam (or 524td cam ) and throttle body, mm I forget which pistons 535i?
you can actuall pump 220+hp, about wut a stock 535 does lol. but a good start would be a 325i diff, as deep as 3.54 and LSD even mo betta ;)
just enjoy the car