at 170 you're somewhere between 154 and 158 depending on board and where you ride. Used is always an option given your budget. If you want new, wired sports will have gear in your budget and they have great cs. Evo and dogfunk will also be worth checking out for nos equipment you'll need to know what you want though.
Don't worry so much about a particular brand and instead focus on a quality board that fits your riding.
***boots will be the most important item you buy, best to be professionally fit and not a place to cheap out.***