There are plenty of custom exhaust manufacturers out there that can make full or partial systems in either mild steel or stainless, some years ago I had a set of rear sections made to replace the end boxes and pipes on an Aero 8, they were amazing and a quarter of the price of the librands system, worth asking around, I'm sure some others on here have done the same and could recommend a manufacturer near to where you live.
I used a local one in MK to do the exhaust on my car - one of those well advertised franchises. To be honest, the quality of work was shocking. Had to go back three times as a silencer kept ripping it's welds - they said themselves that the quality of steel was poor.
Just before I scrapped the car, I had a look at the system under on a ramp. Welding was terrible, with wire sticking out and was rusting badly after three years, rear silencer had been fixed with a jubilee clip and whereas it was supposed to be a 'cat back' system, it was only the tailpipes they'd done.
As usual - caveat emptor. If you do use one, make sure you check everything carefully on a ramp before handing over the cash. Also make sure that they are actually using a proper 'welder' rather than a bloke who's done a bit of metal gluing.
That said, I have seen some very good results, but you can understand why personally, I now choose to DIY!
