Buy the wooden rods and some spray paint, either from Home Depot, Lowes, or Michael's crafts, in the pewter color you need. Spray paint your rods, let them dry thoroughly and you have your solution.

Red

I purchased Kirsch 2 inch wooden rods and and added a thin drapery rod below it for the sheers. Like you, I couldn't find fatter double rods.

The wooden poles in the closet pole dept. are way less expensive than the ones in the curtain dept. Very, very sturdy, too.

1) You can purchase "add-a-rod" brackets that clamp onto any metal rod brackets, behind the primary rod, so you can use any rod your little heart desires. :-) Country Curtains carries them for a very reasonable price, as do Linens & Things and, IIRC, Bed Bath & Beyond.

2) The "Bold Pole" curtain metal rods are 1 1/4" thick and are available in a pewter finish. There is a matching add-a-rod bracket. Country Curtains has them, as do some Linens & Things stores but their stocks are unpredictable.

3) Bed Bath & Beyond's ReSolutions line has 1" primary rods with a 5/8" add-a-rod and comes in pewter. Several finial options. I've never seen these at the store, but YMMV.

4) Pricey, but Restoration Hardware has conversion kits to make a double rod with a 1 1/4" front rod. Their "antique silver" is probably an acceptable pewter equivalent.

Hope this helps some.