Assuming that both are long distance sales, ie no local dealer support, make sure you are comfortable with each selling dealer to support you via phone/email etc. They will probably supply parts, but you have to do all the repairs. Most repairs that come up are not that difficult, but some may cause the average guy some heartache. An example is injecter pump/timing. You would want to use a proven dealer, that has a rep for doing an excellent assembly and check-out. ie all initial problems have been found and solved, prior to shipping.
If you were to find yourself in a lurch, without dealer support for repairs, you are probably better off with the Jinma. Technical support from end users and dealers, is much more widespread. The Kama/TS254 may indeed be superior to a Jinma, but I have not seen enough comments from end users, to say that is the case. Most likely it is a draw. Somethings better implemented on TS, and other things better on Jinma. Given that, and your concern for parts, it would lean toward a Jinma, as well.
Please keep in mind, that I am a Jinma owner, and could ever be slightly biased in my response. /forums/images/graemlins/wink.gif