Well, there's moulded or ordinary.
Moulded are the easiest to fit and are available from Rimmers, TSSC shop and the usual suspects. I think the moulded all come from the same source so it's just a question of price. So probably TSSC. some advertise different sets for rotoflex and non rotoflex and, for the GT6, the luggage area carpet is extra as there are different ones for each of the MKs.
I think the quality of the moulded is not so good, reminded me of a pan scourer, get a sample from the TSSC shop and see what you think.
You can get much better quality with the ordinary carpet but, more expensive, more difficult to fit and the major difficulty is the wheel arches. How do you curve and fix the carpet in two planes to get it looking reasonable? I'm thinking my wheel arch carpet is not badly worn, only faded. So I might get the ordinary carpet and dye my existing wheel arches.
A good supplier of ordinary carpet is Coverdale, www.carcarpets.co.uk They will also send samples.