The trouble is, I don't know what system I should use to give me the same level of refinement I had with the OE one.
I would say an Eternal system might be worth a punt. It's a little noisier than OEM but not in an irritating raspy way .. on a V6 , at any rate. Not too great an outlay to try one either. :-/
The problem with drilling drain holes is that drain holes drilled during manufacture would have been done before the exhaust was galvanised. I suspect drilling one afterwards will provide a nice starting point for the tin worm to get a hold.
Kevin
Exhaust systems are made from pre- aluminised(not galvanised) steel, and any welding, fabrication or drilling takes place after the raw material has been aluminised.
Whenever I fit a new exhaust to my own vehicle I paint all the welds, including the machine weld that runs the length of the tube with a zinc rich paint such as Galvafroid.
I also coat the joints and clamps after fitting.
IMHO it would be a good idea to coat the welds on the inside of the tubes at the rear of the middle section as well prior to fitting if you want to really maximise the life of the system.