Definitely what the others have said: wait until the end of the season, then you can probably pick up a bargain.

As for boots: make sure you get some that are comfortable. Don't just assume that they'll break in. They won't. And boots are (IMO) more important than board or bindings to get right. They can make such a difference between being wobbly and being in control.

As for board size, it depends on many factors, mostly weight and height. You're 6 foot and 13 stone, right? In which case I'd argue that you want something like a reasonably stiff 162. Check out this PDF file from Snow + Rock for more information on choosing a board.

For reference, I'm 6 foot, weigh 14 stone, and I ride a 164.