I went with the HPA 392/728, but it hasn't shipped yet...hopefully within the next week.
Got the H&R 20mm rear ASB, M3 subframe bushings, and the Quaife pumpkin from VAC all sitting in my garage, but my installer wants to wait for the coilovers and do everything at once.
I'll let everyone know how it turns out. Thanks again to Doyle and everybody else who offered advice
RIP 08 E92 335xi 500whp