thanks for all your comments, seems its going to be a nightmare! Will keep you all posted... TalkBansko hasnt let me register but need to have a look at that i think...
You could get the train to Blagoevgrad - takes about 4 hours and about 12 euros, if that, only 1 -2 euros to upgarde to 1st. Buses travel frequently between Blad and Sofia and takes 1 hour. Maybe your best option.