Concidering Insanity

So, My fiancé is going away to basic training sometime before the end of the year. I really want to get in shape while he is gone (8.5 Weeks) and surprise him on his basic graduation (not only b/c he is going to get into the best shape of his life(not that he is out of shape by any means) but also because our wedding will be in August of next year and I do not want to be a chubby bride-ICKK). I have considered doing insanity b/c of all the amazing results I have seen... but I will be honest haha I am kind of scared of it. For those of you that have & are doing it, how do you keep it up even when your sore? When you started were you working out much before then? What were your results like and when did you see them best? ... I have said that I will not go shopping for a wedding dress until I am in my 180s (I am 6'2" btw) currently I am 207lbs.