pipe for quadra 7100

We are going to get Quadrafire 7100 installed. New installation on interior wall, chimney will vent straight up. Instead of enclosing the chimney pipe, we want to build cabinet around the unit, and have exposed pipe exit from the top of the cabinet.

7100 is tested for SL300 and DuraPlus. DuraPlus has stainless exterior on pipe. I can't find any information on SL300. We want the exposed pipe to be black. The dealer recommends painting the chimney black with hi-temp paint. I'm wondering if this is asking for trouble in the long run.

Simpson makes a pipe--DuraTech--that has black exterior. It is an 8 inch double-walled pipe. Can it be substituted for the DuraPlus if it is not enclosed?

Thanks.