Lee, just remember what I said about the flue pipe being under pressure,, not much but a slight pressure.. so you want to seal all joints in the pipe with RTV and high temp tape, and 3 screws per joint..
And have a CO detector near the stove and near the bedrooms. A digital CO detector is best, with a readout, so you can see if you have a small leak [ no CO leak is minor] . Then you can get after it before the alarm goes off at 0400 one morning !
You can get SS seamless pipe and make it so it comes apart in a few large pieces, so you don't have to reseal every connection.. The fly ash is like pepper, very light, but will flow out and make a mess, so you want to plan on the cleaning chore when you build the system.. You might be able to make cleanouts in the pipes, Read up on the various forum members' ideas..