Bimmer: Check e-bay for "used" parts (like engine parts). Sometimes you can find some interesting things on there.
As far as new parts, check places like Finishline, Cobra Valley, Cobrandas, Cobra Restorers Ltd, etc. They all have websites and you can order everything online. As for your floor mats, I just bought some from Finishline (
www.cobraaccessories.com) that are VERY nice. "Cobra" head on them, and the are custom cut for an SPF. Fit like a glove. The only negative is that they don't come with the "snaps" to fasten to the floor like the SPF mats have. They don't seem to move around, but I'm going to try and sew some snaps on them this spring, anyway.
Have fun shopping!!