Well, just a thought, but why don't you go straight to the source?
http://www.army.mil/contact/
https://www.benning.army.mil/pao/common/ContactUs.htm
http://www.marines.mil/usmc/Pages/Contact.aspx
http://www.marines.mil/unit/marsoc/Pages/contact/Contacts.aspx
http://www.navy.mil/submit/contacts.asp
http://www.af.mil/main/contactus.asp
The recruiting websites, etc are also a good source of info and you can contact them as well. For the different tests out there, etc look up or ask about these ones. - I'm sure theres more, this is all I could think up quickly.
US Army
-Rangers, Special Forces. I think for the schools like Airborne, Air Assualt, Sniper, etc you just have to pass the APFT. For the Rangers and SF, I think they have their own PT tests as part of the indoc/selection proces as well as needing to score XXX amount of points on the APFT, once they are in the Ranger Regiment or SF Groups I have no idea if they just use the APFT or have a specific PT test. www.armyranger.com is a site run by a former Ranger and has lots of current and former rangers on it, lot of info there.
USMC
-Recon, Force Recon, MARSOC, Scout/Sniper
US Air Force
-TACP, Combat Controller, Para Jumper
US Navy
-SEALs, SWCC