I don't know any good women's boards, but I can say that if you're willing to spend the money, then a new board will definitely make it easier to learn and help your riding. There's been a lot of 'advances' in snowboard the last ten years, not to mention that a ten year old board that you probably didn't stow away very carefully is probably the worse for wear for it. And at your weight I would probably go a few cms shorter, I ride a 157 as a 160 lbs male, and I could stand to shave a few cms off. 153 or so should be a good length. Look at last season's boards, and you'll save a lot of money.
But I second the above post on getting boots first. Go to a shop and try on every boot in sight until they kick you out. Whatever fits best, get it. You want a boot that's as tight as possible without being uncomfortable.