I am buying a Knight Disc 50 cal. and will be shooting a max distance of probably 200 yards with it and am wondering what kind of scope I should get with it. I am new to the blackpowder guns so please help me out. I don't want to spend a fortune, I have been looking at the following and wonder what you guys think or if you have some others in mind...Bushnell Trophy 3-9x40 $99; Nikon Prostaff 3-9x40 $149; Simmons AETEC 2.8-10x44 $149?

Thanks,
Joey