We're both taller and heavier than you and find the bike very comfortable, especially on cool days. On hot days...well its just hot.
I have a 55ltr Givi and we can do a 2-4 day weekend with all the trimmings of clothes for the beach, the bar, the club etc. Beyond that I guess we'd just have to wash a load.
2-way coms help a lot, I doubt my wife would enjoy it as much without the tunes or talking, I have a starcom1 digital but there are plenty of choices.