Steve (SP32) had one built by them on his 3.2, the car was bought by a member on here and is currently on ebay if you want to see pictures.
Only thing I would say is, if you go to any of these custom exhaust centres with a V6 insist that you have a twin pipe system all the way through, they will try and sell you a single pipe and get round any issues you may raise by saying that they will put a bigger pipe after the join. Anyone who has driven a V6 with the proper spec exhaust and a single 'mid' pipe exhaust will tell you how flat they are compared.
Thanks, good advice 
They will make it what ever spec you desire, twin centre or single centre with a 'Y' joint.
But if you chat to them on the phone speak to Andrew the Boss and explain exactly what you desire and what sort of sound you want.
Mention I was there yesterday and I have recommended you, I am trying to get them to sponsor me for The Rally For Heroes 2012 European Tour. ;-) lol
Also explain what sort of rear outlet you need, Single, Double, Single each side or Double each Side, this will reflect on price.
They are open 7 days a week as well ;-)