If you're in the US, try the Stockroom.com, and look for the Terra Firma style harness. There are 3 models - nylon webbing (for vegetarians, I guess), leather with buckles, and leather with D rings. The harness is solid and well made, and the 2 straps running underneath can surround the device, which makes it more comfy than the single strap style. Also, if you're considering a dildo, we like the Vixskin models because they are so lifelike. The Stockroom sells them, and so does Blowfish.com - Blowfish sells them under the Boitoy name.
You might try Mr S leather