I'm doing that with the Magnaflow #11366. Mufflers with stock tips and getting a custom x-pipe made to replace the front resonators and will leave the rear resonators in for now.
If anyone is interested in a custom x-pipe, i can see if he can just fabricate an extra one when he does mine next friday.
645Ci Convertible: Sport, Winter, Audio Package
Mods4Cars smartTOP E64 Convertible Control Module
Limo Tint for Rear Windows
Magnaflow Exhaust with custom X-Pipe
20" M6 Replicas, H&R Spacers 20mm Front & Rear
Falken 452 Front: 255/35/20 Rear: 285/30/20
Eibach Springs 1.2" Front and Rear
AE's: MTEC V3 LED
DLR's: OSRAM NightBreaker Plus
Low Beam Lights: OSRAM Cool Blue Intense
Fog Lights: Hid-Kit
Parking Lights Delete
Turnsignal Lights: Stealth/Chrome