chimney liner?

hi, sorry if in wrong forum... Am planning on buying/ordering an Accentra insert tomorrow. Am looking at installing the liner and air intake myself then having the dealer install and set up the stove. Anybody have any recommendations on what is the best chimney liner? Is it worth the extra money for smooth wall piping? Also, I want to run an OAK, but the existing masonry chimney is on an interior wall, The OAK will have to feed from the top of the chimney. Can you recommend a "binary" chimney cap that will accommodate both intake and exhaust? Great forum. Lots of knowledgeable folks here.
thanks in advance
-mike

to bad your so far away i have a brand new liner cap and trim for sale

Harman has a chimney cap that has a solid plate on top with a hole where your exhaust pipe goes. But the bottom is screened so you can terminate your OAK well below the exhaust in the chimney. You probably know you have to maintain a set distance between the OAK and exhaust (it's in the install instructions). That's how mine is installed. Good luck.