dont think that there is a reason not to get a good binding except din range since your big enough. I promise you will be able to use a good pair of bindings for a long time, so dont skimp on them because they can save you knees and life, no matter how good you are.
as far as the good ski choice, look for a ski with rocker because this will be more versatile and will be easier to control. it will also allow you to have a proper length ski, but allowing you to use progression to get to the point of being able to use the extra length(i.e. running edge length) considering this, I would recommend the Rossignol Storm. Its a rockered ski that can handle a bit of pow, a bit of park, and it shred like all rossi skis. you can find great deals on them, and i even helped a friend of mine out by showing him them and he picked up a pair and loves them. he is in a very similar situation as you so I think im leading you in the right direction,
sorry i couldnt find the 180 length, but you can always just go to shops and get a pair that way