Ancestry Managment.

[Biggles50]

That is a fantastic position to be in.

The 2000cM does look like a half sibling and that would be a good initial presumption to make.

It is in the same ball park as the amount of DNA that I share with my Half Sister who I found last year, for us we did not really need her to take a test as we look so much alike and when she showed me a photo of her Father (who her shared DNA with me proved that he was also my biological Father) it was like looking at a photo of me when I was fifty.

Unlike documentation, citations etc which whilst being helpful they can be in error, DNA does not lie with levels of shared DNA above the false positives area.

Good luck with the research.

[Steve3180]

Just to add that when you're looking at relationships this close the number of segments you share is also relevant.
A maternal half sibling will share about 50 segments whereas a paternal will share about 32. The dividing line between them is at about 40 segments with a small overlap.
This gets less useful as you get out past grandparents as the overlaps get much bigger but is worth bearing in mind when trying to place close relatives.