Thanks for the tip Vidaloco
His feet were a bit rounder than we had thought, his fronts are as wide as they are long - and that's with the pathetic wall he currently has, so will get even wider when that thickens up! (Trimmer recons they are going to be beautiful feet once this new horn grows down more, it looks very healthy and strong!)
His hinds are just going to fit width wise into the Edges, so will go ahead and buy a pair. My trimmer said there is a little more width we could take off by making a bit more of a mustang roll if we have to, so fingers crossed!!
Looks like I will have to wait until they bring out the 'wide' version of the easyboots that apparently they are working on at the moment for his front, but his Old Macs still fit him so they will do for now.