Hey Caz,
Not to be rude but it sounds like you've answered your own question.
If you have no dealer support for Dolmar, and this is an issue, or at least it sounds like it is, would suggest another brand ie Husky or Stihl, that has a reputable servicing dealer in your area. You may pay a little more but the piece of mind the extra dollars buy may be well worth it.
This is not to take anything away from the PS5100, great saw with an excellent price point. It's a decision you have to weigh and make.
Good Luck whatever you decide.
Take Care