I have had KW V2's since August 2015 and have not had any issues with them so far. (fingers crossed)
We have very bad roads here and the way they soak up the road imperfections at higher speeds is just great.
The next step is definitely subframe bushings (or inserts) and maybe lower control arms; then I think it will be perfect for my needs.
You'll probably not need all the adjustment (rebound & compression) on a street car, but since yours is a cab there might be issues with the ride height because of the weight of the car - there are no E88-specific springs on the market and most of the aftermarket springs give 135i's too much positive rake. Depends on whether you want to dial in the perfect ride height, too.
Turner lists Bilstein B16 PSS10 for $2022 which almost fits your $2k budget. I would consider those.
My 2 cents... I am definitely no expert in this field.
