What size compact track loader?

Been searching the net but haven't seen any good info on this application. Need a track loader to shove 108 50-60 lb bales of small squares of alfalfa into a box trailer. Would be pushing 6 wide x 6 high x 3long bale stacks loaded onto platform with tractor and grapple and going in endwise to 48-53' trailers. Platform is steel truck bed, trailers may have wood or metal floors. Have been loading by shoving in layers with grapple but still have to do some stacking, so looking for something easier. Don't have any experience with the compact loaders, don't want to get something too big because we have tractors and loaders for that, but I can think of several other uses for a track loader. Have dealers for most all brands nearby. Any recommendations appreciated.

What size compact track loader?