http://www.parts-express.com/cat/grill-cloth-fabric/651The premium black cloth looks pretty nice. IMO, the powerful SP waveguide tweeter won't mind a touch of fabric covering. Might attenuate by .5dB at the very top, even less below.
As for the stands, there are a lot available. Audio Advisor has a selection of low cost stands. $130 for a steel pair. Used to be cheaper, but even Made in China doesn't mean what it used to. But they look nice, steel, sand fillable, if appearance is what you're looking to improve, might be the best bet. I just don't know how good the quality really is. Is it welded or bolted?
I built a pair of stands from plywood. A 6" square column is capped by double layer plywood 12" square on the bottom, the column filled with dry sand and the top is 6 x 8 x 2" thick on-edge laminated ply. They weigh about 20 pounds ea. They probably aren't as good as heavier, rigid steel with spikes, but they are solid no resonance, and very cheap. If I would do it again, I would use three or four 3" PVC pipes per side, glued to top and bottom plywood caps with PL urethane adhesive, filled half with lead shot on bottom and fill it up with sand.