dj service for reception only?

I am considering options for music for my ceremony and reception. I think I'm going to go with a guitar guy or something for the ceremony and cocktail hour and I really just have basic needs for a DJ type service such as emceeing our entrance and hitting play on playlist. Has anyone gone this route and if you have any suggestions on trying to find a DJ for 3 hours versus a full event? We've also considered doing this part (hitting play on playlists) ourselves but that might get a little tricky