I'm just gonna give you some boards I've been looking at for freeriding that I mentioned in another thread.
Ride - Highlife
K2 - Slayblade
Arbor - Element
Never Summer - Heritage
Just to make it clear, I have not ridden these boards so I do not know exactly how they perform. But from reading reviews sprinkled around the net I do know that others have enjoyed them and they're something to keep your eye on. Basically putting those names out there so you can somewhat jumpstart your search. Those are higher-end boards so you will have to look for last year's model(if there are even any left at this point in time) to get them under $300.
The boards I listed lean towards the stiffer side(except maybe the Element). A mid-flex all-mountain board with plenty of dampness might also suit you fine for what you want to ride. At your shoe size you may need to get the wide version of some boards... this part I suggest finding a local shop to measure up your boots to the board in person. The waist width measurement given on websites can be misleading.
I'd also personally get new bindings to match a new board, but that would put you over budget so you could always shoot for that for next year.