good luck man. boots will not be perfect for you but hey if your budget is small and you have them at least give them a shot. as far as jacket goes. if its waterproof and warm it will do for now, im sure you'll upgrade soon enough. most important thing is to be dry and warm or youre gonna have a bad time so maybe consider getting some decent pants and gloves, they will make a huge difference to your comfort level. as for board check out craigslist you should be able to get some sweet deals being so close to all the big mountains around seattle. probably one of the best spots to be, big canadian mountains close by too. from your weight description and shoe size id say your probably a taller thinner guy right? im just over 6 feet large size 11 shoe, about 190lbs and i ride a 157. but board size is dependant on weight, type of riding, type of board, shoe size, personal preference. so way too many factors to tell you a specific size but 154-161 is a decent ball park. there are many types of board profile aswell.
check out http://www.snowboardingforum.com/boa...g-between.html
to see what you think you might like
also check out http://www.snowboardingforum.com/boa...ease-read.html
for gear etc.