I'm jumping in from the April board because I saw this pop up in the current threads and wanted to say I'm going through the same thing. I've been seeing PT since I was 28 weeks (I'm 37 now) and it has made a HUGE difference. If your PT hasn't mentioned one yet, the serola SI belt has literally been the one thing keeping me moving so far.
As far as c-sections and SPD, everything I've seen has said that it isn't a reason to get a c-sec. You'll still recover more quickly from a vaginal delivery and it makes sense really once I started thinking about it. SPD is from your pelvis not staying locked in place, but your pelvis has to unlock to birth your baby. My PT has given me a list of positions to labor and deliver in to keep pressure off of my trouble areas. I also have seen countless people say that it had zero affect on labor and delivery compared to their other births.