I’m not sure there is a “standard” 2+ trailer. Who builds the best is like asking is Ford better than Chevy or Dodge. We’ve done 2+ trailers that were only 18’ on the floor and we’ve done 2+ that were 28’ on the floor. It depends on what you want the trailer to do and what size horses you hauling and you do with them. We’ve done several that are 24’; 11’ standing stall, 7’ open area, and 6’ dressing room. This may not be what you need but there aren’t any dimensions that are cast in stone. The trailer will last you for 20 years or so, get what you want to do the job at hand.
Here’s a 25’ we did last fall.
Dave McAdoo
Tobruk Trailers
since 1984