Well spent an hour with them discussing options, what I wanted sound wise etc, OEM looking tips or something different. Flanged Decat options as well so cutting the cat out and building a straight pipe which can be easily swapped out. Really friendly and the merc they were finishing sounded and look very good.
Quote for half system (not standard cat back) as they said they'd want to have a box along the straight pipe, then box replacing existing box, then pipes all the way to the back without the suitcase. Keep the pipe work the same bore all the way along (2.5 - 2.75), slanted tips 3 inch non rolled to appear slightly bigger but still OEM looking - ish. £399
Reason for going past the standard cat back was in prep for a decat/sports cat option.
So now just to have a think