First off, welcome to the forum. It is good to have you here.
The Black Diamond with the 22 inch barrel is all the rifle you will need. Especially in Northern Wisconsin. It would be easy able to hand shots out to 150 yards if you are good enough with a peep sight to shoot that far. I have used a Black Diamond XR for many years. Although in all the years I have owned it I have not been able to score a deer with it. Not that I did not try, the deer never gave me a shot, and I hunt with a number of other muzzleloaders as well.
The Black Diamond is a good shooter. 100 grains of Pyrodex and a 250 or 300 gr Shockwave and you should be in business. It would be able to take deer well past the 125 yard range. The BD shoots a lot of different projectiles including conicals in my rifle. Some of them are XTPs, Shockwaves, PTX, maxiball and a number of other things. Plus you have that Thompson Center guarantee behind you.
I am currently shoot a White Ultra Mag .504 caliber with a T/C 1X scope so it is legal in Wisconsin. I think this is a better way to go then a peep sight IMO. Plus if you put Warne QD rings on it, you could mount a different scope in similar mounts and use it during the modern season as well.
The Black Diamond has a few disadvantages as you will come to discover. They do fowl the breech a lot. They have three different ignition systems, which makes it real handy for you.. The 209 will handle all kinds of weather for you. When on the range, be sure and twist the breech plug every 10 shots, to make sure it is not seizing up on you. Other then that it comes with great fiber optic sights. They are well balanced and shoot great. I like them a lot.