ATV extras and trailer size

I’ve been looking into getting ATVs for the family. A friend that rides has all Polaris, so that’s what I’ve been looking at. I’m wondering if I need any of the "extra" stuff though. I want to get a plow for one, but other than that, is anything else necessary? Handguards seem like they would be useful. But what about brush guards, the racks, the storage box on the back, etc? I can appreciate how nice the things look, but how often do they serve a real purpose other than aesthetics?

Also, I can’t figure out how to determine what size trailer I’d need to haul the ATVs. I’ve been looking at getting two Sportsman 570’s and then either a RZR 170 or Outlaw 50 for the kid. The 570s, according to the Polaris website, are 4′ wide. I’m guessing most people side load when they’re doing multiple ATVs, so I’d need probably a 10′ trailer for two 570s. The Outlaw 50 is about 3′ wide, so now I’m at maybe a 14′ trailer. But the RZR is much bigger than the Outlaw 50, and longer than the 570s. Am I going to need a trailer that’s like 8′ wide by 14′ long? That seems really big. Searching online, the biggest I saw at Home Depot was only 6′ by 12′. Will I need to have a trailer custom made somewhere?

Any advice would be greatly appreciated.