Well I got my mid pipe and backbox from the bay for £112. Fitting was not too bad, no worse than trying to remove to stock original really. The mount on the mid pipe needed a tweak, and drivers side tailpipe sat higher so made some spacers (4 washers in a stack) to fit between the hanger and chassis to lower it a little , Job done.
It sounds alot more up for it than the stock one, although I would like a little more, Would a 'Y' pipe alter the sound any, or do I need to replace cats as well?.
Overall I would recommend if your in the market for a cheap repair to replace a rusted stock item.
Cheers.