Having used only one (23 and Me), I can't really comment on the others. You might want to look at the DNA descendants on his profile page and see what they used, although it probably doesn't matter. I don't think they're very different. I went with 23 and Me because that's the company my brother used. My BFF, a respected genealogist, used Ancestry, but I have an irrational aversion to Ancestry in general. Then consider registering your results with GEDmatch.
23 and Me will give you your ancestry background for $99, as well as a list of their clients who have matching segments of DNA. GEDmatch is free and will show you their list of people with matching segments--from any testing company that registers with them.
Hope this helps. Good luck!