Hiring a DJ would probably be the best bet, because they will haul the sound equipment in, have a library of tunes, and make the necessary announcements. But, it will probably be difficult to grab one on such short notice, especially for a June wedding.

Absent a DJ, I would strongly suggest that you delegate the sound equipment chores if you plan to use it for the reception. Renting pro audio equipment is a great idea because those rigs travel better, will play louder than a typical home system, and will tolerate little "accidents" better than home audio equipment will.

I brought my surround speakers and an old AV receiver to my wedding basically to play the bridal intro. The speakers got damaged (not that I cared, because they were my wife's old Bose 301s and we were ready to get rid of them anyway) later on. But, again that was for the ceremony, when everybody in the room was at attention.

For the more raucous reception, we had a live band and used their sound rig and the sound man played tunes in between sets. For a reception, you might need something that can fill a room better and stand up to abuse better than a home audio setup will. As others have said, it will depend on the size of the room and how loud you need the music to play.