Travis,
I would ask for a copy of the warranty in writing. It is definitely not a national warranty, make sure he is not mis-leading you. One of the problems out there in the market is that some dealers lead you to believe that you can go anywhere with the tractor, and that is simply not the case. Allot of owners of grey market and older american tractors tend to be tinkerers(not sure if that is a word?) or fairly self sufficient and alot of us do our own repairs simply because we enjoy it(no one touches my D3250 but me... probably why my repairs take twice as long). As long as you don't mind turing a wrench once and a while they are great tractors and you can learn a ton, although it seems you may be making an equal number of repairs on a jinma if you read the boards. The folks here in this forum will always support you with Yanmar questions and repair tips.
As far as the YM2000 it is the honda accord of tractors, dependable, simple 2 cyclinder, very versitile, and parts are very easy to come by. Not sure if anyone in this forum would recommend a Jinma. I have never owned one so I really can't help you there. However, I can tell you a YM2000 is a great choice.
Best of Luck
Bob