Hi Dexx,
There's two camping areas at Big W; Capt Logans camp & Lumley Hill. They're right next to each other on adjacent points. Fairly quiet most of the time (one good thing about no powerboats is there's no skier yokels as well).
No shops close by, nearest would be a coin toss between Fernvale, Cominya or Esk.
I would think you'll have to book a campsite for Easter & I'd hurry. They commonly book out. Great place to camp, amenities are good. Think Lumley Hill has powered campsites as well if that's what you need.
Would call SEQWCorp info centre on 5427 8100
Cheers,
fitz..