If you look at the NRA records for competitions where both scopes and iron sights are allowed you'll find the scope scores are usually higher than iron sight scores but not by much. Do not automatically reject a good set of iron sights.
Sometimes the iron sight shooter gets real close to a scope shooter. This is an interesting read about George "Dad" Farr:
For round bullseye targets this means a rear peep sight and an aperture (circle) front sight.
If you are going to use a scope, especially at longer ranges, be aware it can magnify the effect of mirage greatly. To the point you cannot see the target if the magnification is too high. The Army Marksmanship recommended 15X max at 600 and beyond IIRC.
Don't know you age or how good your eyes are. Scopes eliminate a lot of problems caused by vision that is less than excellent.
