Definetly go with a cheaper rifle and add a muzzleloader. The only reason I can see to spend more, if your budget is limited, is if where you hunt you would need to make 300+ yard shots.
If where you hunt is typcal of lots of us, then the longest probable shot would be 150 yards, and for that shot you don't need the most expensive steel and glass.
Remember, you wll need to buy ammunition, BP, bullets, cleaning supplies, loading equipment (for BP), cases, slings, targets, ect. I would try to get both the smokepole and rifle for around $800 and then youhave $300 to spend on everything else you will need.
Or, alternately, do what I do and tell the wife you spent $1100 when you really spent $1600:-)