Last year I built my own hot air jacket for my Pocono back vent. My design is a bit differernt than most hot air jacket implementations, but it works quite well!
I have my stove sitting right next to my forced hot air furnace, when I installed it 6 years ago I simply had a 12" collar welded on the top, and I used a 12"elbow and ducted right into the hot air side of the existing duct work. I simply using the 2x 256CFM blowers to move air from the stove into the duct work, and throughout the house. This worked fairly well until it real cold and windy, then we had to supplement with the oil furnace. I really liked the flexability because most of the heating season, it was sufficiant, and it kept the house very consistent.
What I ended up doing is quite unique, comparded to most hot air jacket installations. With typical jackets, you duct the stove into the cold air side of the furnace, remove the 2 convection blowers, and install a fan limit switch in the duct near the top of the stove in parallel with your existing furnace fan limit switch, and let the furnace blower pull the heat off the stove,
and into you existing duct work.
I left my 2x 256CFM blowers on the stove, left my 12" duct into the hot side, just as before. I then built a jacket around the 12 inch duct on top, and around the sides, much like the commercial jackets. I then cut a 10" round hole in top of the jacket, connected a 10" elbow, and ducted it into the cold side of my furnace, installed a fan limit switch in the duct near the top of the stove in parallel with the existing furnace fan limit switch.
This way in average temps, especially in Fall and Spring, the 2x 256CFM blowers on the stove push heat off the stove and into the hot side of the furnace duct work and into the house. When its cold and expecially windy, when the stove is working, the limit switch kicks on the furnace blower and pulls the heat off the sides of the stove, and into the furnace duct work.
This may sound crazy, but it works very well. Typically the furnace blower won't kick on until the feed rate is around 55 or so. It took me a while to get the limit switch kick on/off set where it worked the best. We have an old 2200 SQ foot 2 story farm house, and live about 1/2 hour NW of Cortland NY. If the wind isnt blowing, it will keep the house at 69, when its 16 below zero, zero, with the feed rate in the 70- 80's.