what would you all recomnnend the best liner for an hampton HI300, interior chimney 25 ft. long, 6in to wood insert? I plan on making my own backing plate with sheet metal and roxul insulation. I need to order the liner,(what website is the best to order from) I measured from cap of chimney to floor of fireplace to give me extra length to play with. Somthing thats going to last me a long time and with stand many cleanings.