Thanks for all the advice everyone, I really appreciate it. I appreciate the heads up about the toughness of the special forces training as well, but I have been well aware of the hell that these men go through in training for a long time; I've seen the video set above already as well. That said, I'd still like to give it a go. I've begun training already and will have another two years or so to prepare before entering the program, so I think I stand a good chance in training.
As for the biology degree, if it's a tried and tested path that'll get me to PA school, I think I will go with that route, mostly because if I go the nursing route then most of the credits I have already accumulated won't transfer to a BSN.
Thanks for all the help everyone! I really appreciate it!