Anyone with a 142a Mossberg?

I've had this since I was 12--70 years--and just brought it out but find I can't shoot it as accurately as I could then so want to add a scope. If you have done this I'd be interested in what you used. BTW, one of the reasons I have it out is because my grandkids are now 12 and I think it is time they learned to shoot and this is a good place for them to start.