Harrington and Richardson, I believe make a good economical one. Thompson Center makes a very nice one. Good thing about these are you can buy interchangeable barrels for other calibers or shotgun.
Nothing wrong with a single shot they tend to be accurate and make you a more accurate shooter/hunter as you tend to be more critical regarding shot placement when you know you likely have one shot. Though with practice you can reload pretty quickly.
When it comes to scent, there are basically two types; those that attract and those that mask. I've tried both on many occasions. There are lots and lots of "doe in heat" scents, designed to attract a big buck into range. I've also used a "cow in heat" scent while elk hunting.
Another scent would almost be better named as a "coverup smell". The main goal is to cover up human odor or mask it. Though I don't believe you can ever totally eliminate all human...