I had an 186D and it was an awesome machine.
Overall it should be pretty safe. If it doesn't have a ROPS, check with a parts dealer. Sometimes they are FREE, otherwise about $450. If it is a Powershift model, it'll relly be nice with the loader.
I agreee, I'd take a used Yanmar over a lot of the new machines you'll see...
YM276D is definately a US model, so you can get parts from Yanmar US.