Hey Dennis,
I havn't been past Moreton but you will want at least a coupla weeks for such a trip. I dont know about up your way, but you will certainly be able to sail from the bay to the Gold Coast unless a South Easterly when coming down the main channel, at which time you should give up and motor.
If you dont have the Beacon to Beacon yet,, go buy it, its all you need.
Good stops including St Helena Island, Tangalooma and BIg Sand Hills (not in a Westerly though), Horseshoe Bay Peel Island is a real nice anchorage. Blakeslys anchorage is nice enough. You need to decide on the Canaipa passage or Main channel once you get to the bottom end of the bay. Canaipa passage is a little more interesting but lots of bends and only really good for motoring in the Mac. Main Channel is faster but pretty boring (no good for sailing in a Southerly)
You can stock up on Fuel at Horizon shores or Ruddy Maas and there is a small supermarket at Jacobs Well if you need food.
Very nice stops then are Jumpinpin and/or The bedroom. Not far South is Tipplers passage which is a nice calm place for a night or two. From there, a straight run down the Channel into Southport. Plenty of decent places to anchor in the Southport Broadwater. Bums Bay (Marine Stadium) near seaworld,,, or even right out of the front of the Seaworld carpark there is a nice little sheltered spot behind a tiny island. The hole behind Wavebreak Island is a nice spot to anchor. If you want convenience for shopping, public transport etc, A fantastic place to anchor is at the Broadwater parklands right next to the enclosed swimming area. (On google Earth, see the swimming area with the big person shaped swimming platform - Anchor either side of this swimming area). In the Google Earth photo, the parklands havnt been developed yet, but its all a kind of a kids play area now (very busy on weekends) and easy access to the shopping centre. A good thing about anchoring here is it is a real steep beach so you can back the Mac in and step on and off. However I have twice had children dig up my stern anchor there. If you're taking a dinghy thats not a problem.
If you want to lower you're mast, you cant turn it into a Canal cruise and go into Surfers, or down to the Casino in Broadbeach if you really want..
I dont know if you vist Trailersailer place. Theres some very helpful people there and you will find some useful info. You will cop the odd childish comment based on the fact that you own a Mac, but I dont let that get to me too much. Back when I had my Careel, I was deffinately Jeolous of Mac owners too so I know where they are coming from

Just Search for Moreton Bay cruising or similar. Heres some stuff to get you started.
http://www.trailersailerplace.com.au/ph ... lls#p80109
http://www.trailersailerplace.com.au/ph ... oma#p86433
Having said all that, I dont recommend such a trip for a while. You need to get the bugs ironed out and get used to the boat and how it reacts to wind, waves etc. There are usually some mess ups and bad days when you are getting used to a new sailboat. Its better to be close to home when things start going wrong.
Stick close to home for a bit and tackle that trip later...