I don't think they make a permanent mulch all mulch has to biodegrade so it can keep feeding the roots of the plants it is covering. The best place I have found as a really good information source is your local greenhouse they have tons of pamphlets they can give you as well as their own personal knowledge.
Use a large rock look called a large wood chip. It comes in big bags and looks great! It lasts longer then mulch and stands out better from the street.
Rounded river or beach stones make an attractive permanent garden mulch. Weed block fabric under the stone will keep weeds down, yet allow water to percolate through.
The different types of mulch are wood chips,leaves,straw,news paper or shredded paper,pine needles
,landscape fabric. Using this type of mulch your garden will get a look.
I recently used recycled tire mulch. It generally comes in black, brown, or red and runs between $8-10 per bag. I laid weed prventive fabric down in my flowerbed and then covered it in mulch. Haven't seen many weeds but they still pop up once in a while.
