Akrapovic is the only exhaust I'd consider. Cost a few quid though.
Yep, £1700 for pre FL and more after as you can't just have a slip on so have the downpipe and cat so about £3600. Iy's a a hell of lot and not much point unless you are tuning the car further.
I tried to get an Akrapovic on mine, but sadly it's very complicated and not yet street legal for the 7.5 in the UK.
The new 7.5 products are now starting to appear, and the 'slip-on' is possible without the downpipe & link, but it's stupid loud and you lose power (and it causes ECU errors) due to back pressure. To cure this you have to use the downpipe & link kit, but then it breaks emission levels for road use, so isn't street legal in the UK. Fine for track, not yet ready for the road.
When it's ready for road use I'll be getting one, along with the APR SP3 remap. I think this is an ideal combination. The tuners I have spoken too are hoping all this will be ready by the end of the year, which from my side will also be when my engine is properly bedded in.