John,
the landscape for red dot optics has never been better. You have many choices that are “adequate“ for your Taurus. Many are under 200 dollars. 200 is kind of a good threshold for median red dot. The quality really increases from there. But for your Taurus several of the less than 200 optics would likely suffice just fine. Most all the red dots today are manufactured with co witness iron sights in mind. By same token most of the manufacturers today are making taller irons to accomplish just exactly that. Getting your Taurus to co witness is not a problem at all. I would Google the Taurus forums and see what folks are using.