The Honda Silverwing is way more than a scooter with up to an 800CC twin V engine. It will most definitely carry two and go highway speeds easily. The Suzuki Burgman comes in a 400cc and I believe a 650 version, also quite capable but neither are as cheap as the 50cc varieties, of which you would need two. Stay away from anything Chinese. No offense to their otherwise industrious capabilities in manufacturing but they are not yet up there with the Japanese for reliability.
For anything big enough to comfortably carry two, I think you may need an actual trailer. We recently bought a Kendon, ride up, one bike trailer for our Yamaha FJR1300, slightly larger than the scooters. It weighs about 350 and the bike is 700+, so around an additional 1050 pounds to tow on our 32' Greyhawk.
We just returned from 9 days in NM and CO and used the Yamaha in a few places to sight see and hit the grocery stores.
Keith (& Teresa)
2017 Greyhawk 29ME
Dallas/Ft. Worth, TX