I still think OEM is the way to go.
Either E34 M5 bumper or the stock E34 bumper with a lip or add on. I really don't like that Sidel kit, I hate how they molded out the bumper moldings, it doesn't flow very well with the rest of the car.
You could always get another RD bumper from Eurostyle.
BMW M-Tech (Same as mine)
I forgot which this one is, I think it's hartge?
Alpina (Very hard to get)