If you've got plenty of opportunity to practice, I'd go with the Ride Antic. Stiffer so it'll handle freeriding better than the agenda. A 2010 runs around $400, but you might still be able to find some 2009s at a better price. I also like the Forum Destroyer. I think its still technically a freestyle deck, but I still felt like it was stiff enough to handle just about anything. Again, a 2010 destroyer might be a little out of your price range, but get a 2009 if you can.
You can also look at the Ride Control. More of an entry level deck but more in your price range for a 2010 model. I've never ridden one, but my friend started with one and he's probably better than me now.
Evo | 390 | Kaiju