I would buy the Outdoorsman medium for about $350 but if $300 is max I would get the Slik Pro 624CF, it is my backup for scouting as it is about a half LB lighter than the Outdoorsman but not as tough.
BB
I have the previous generation of the Slik carbon and it is great! My buddy just got the Promaster carbon from S&S Archery and it is very nice, but a bit heavier than my Slik.