Acapella Audio Setup for Backyard Celebration

I need a professional audio setup for a five-person acapella group at a backyard celebration for 100-150 guests. I require both portable speakers and a mixer. Key Requirements: - Five microphones (brand/model... (Budget: $250 - $750 USD, Jobs: A/V Systems, Audio Editing, Audio Engineering, Audio Production, Audio Services, Music, Sound Engineering, Voice Talent)