Koyker makes a good quality loader. They have most of the yanmar grey market models listed on their site but I'm not sure which one is similar to the 135d so you'd probably have to call them, or a local koyker dealer to find out if there's one that can bolt up without any modification.
I'm going to build one for my YM146. It weighs about 850lbs, but if the small Craftsman tractors can have them and use them, ours should be no problem. It won't lift as much as a big tractor, but some is better than none in my book.