Me and 18 of my friends booked at K resort about a month ago...you really do need to get in so early. I couldn;t believe it when I saw how much was sold out even when i went to book and it was early october then.
schoolies.com has had some reliability problems but there is one thing to be said about it, and that is that its bloody easy to pay and organise everything with your friends..everyone is responsible for themselves and gets their own password and account, and then theres one organiser who has access to everybody's stuff. Its very easy to use though and theres alot of support.
From what Ive heard its totally cool going the other way though,mthrough a travel agent or other websites, it just requires alot more organisation on your part which you might not have time for.