October 2026 wedding: 100 guests, 5 hours, no alcohol. Units needed?

We're planning a small wedding in our backyard for October 2026. It'll be about 100 guests, no alcohol served, just a daytime ceremony and lunch reception over 5 hours. The ground is flat grass, and a truck can drive right up to the spot where we'd put the units. I'm trying to keep costs reasonable but don't want anyone waiting in line. Should we go with standard portable toilets or consider a deluxe unit with a sink? And how many units would you recommend for a crowd this size without alcohol? Also, do we need an ADA-compliant unit even if no one has mentioned mobility needs?