Drew:
Sorry for the delay. My in-laws arrived yesterday for a week long visit, and I was quite busy with cleaning stuff up to make the place presentable.
I did not go all out with the sound containment around the doors yet. I installed a cheap vinyl door bottom to keep light out and some sound in.
http://www.mdteam.com/products.php?category=1800
My threshold is made from hardwood and does not have a vinyl insert.

Quite frankly, I didn't spend a lot of time trying to think about these items. I can change them rather easily if I need to later. I also have not been able to get test them out and see how much is leaking past them. I doubt that there is much sound leaking out now, but I need to test it and see for sure.
I hope to figure out the weatherstripping needed between/around the doors this weekend and get it installed. Also, I hope to install the door stops and handles, and get the jambs and outside trim painted.