Personally, knowing what I know now, I'd look for a good used fork. Like I said, I have a RockShox XC30 and it's ok, gets me by for now, but I've seen good forks go on my local classifieds for only $200-300 which is good for a fork.
If you do want to buy new, I'd recommend the RockShox XC32 as the lowest-end.
And of course, feel free to hit me up for advice, especially drivetrain stuff.