What Spenac said was pretty much spot on. Our website is at www.atcems.org, check it out. If you're about to be certified as an NREMT-P I'd apply for Austin as soon as you get your card in the mail. You won't be able to apply for an ambulance position until you are certified as either an NREMT-Paramedic or Texas paramedic. If you have to wait for whatever reason, I'd recommend Marble Falls Area EMS (not sure how easy it is to get on as a basic) or San Marcos/Hays County EMS for a little 911 experience.
Search and Rescue...we have three "rescue" trucks, the people in rescue are trained in swift/still water rescue, land rescues, high-angle/low-angle stuff, trench rescues, cave rescues...all of that stuff. We also have a tactical paramedic ambulance that gose on all APD SWAT calls, and a HAZMAT truck for all of the methyethyldeath scenarios. There's a testing process to get into rescue after you've finished the academy and cleared to independent duty. The bike medic stuff is all run by ATCEMS paramedics, unless a special event chooses to contract out to a private company like First Medical Response, AMR, or S.W.E.A.T.
Let me know if you have any other questions.