Mark,
I must admit I am a bit of an Airbus fan so I really wanted a decent Airbus simulation. Unfortunately I read a couple of reviews regarding the PIC version that put me off. I hear the FMC (or MCDU in Airbus Speak) is not as well featured as most would like and is limited to importing flight plans from FS2004. (It has no Navdata of it's own and can not take complex flight plans) ***Edit this is incorrect, it has a functional FMC, it only has a clickable 3d cockpit though, no 2D panel and it is pretty harsh on your frame rates, see the review here:
http://news.pcaviator.com/downloads/a320.pdf ***
I have the PMDG 737-8/9 and this is as the others have said before me, a great product. I have had it for 3 weeks now and still find myself sitting at the gate for 30 minutes prior to my flight setting the FMC up and going through the startup procedures.
If you want an Airbus, I would personally recommend the PSS Airbus Pro package. It is starting to show it's age a little but it has a full function FMC and realistic Airbus systems although the flight dynamics are a little suspect. You can download the Airbus Pro base pack with only the Airbus livery for about £15 sterling. ($35 - $36 AUS) It has the base models of the A319, A320 & A321 each coming with 2 engine variants, so essentially six aircraft. You can purchase seperate Liveries but these are pricey although on the PSS site there are a lot of free ones available too. Of course there is no EHM repaint for this plane and unfortunately it is not compatible with the ProPilot system due to the fact it has a strange landing light system whereby the lights are turned off when you retract the gear resulting in a penalty on takeoff and landing. All in all though, it is pretty good value for money and not a bad product, be warned, if you have any problems with it you will have to trawl the forums for a solution. (For instance, it has a battery problem so unless you have a registered version of FSUIP, you have to start the sim up with the default 737 and then switch to the Airbus) It is also sold in a Boxed Version by "Just Flight" for a bit more but with more liveries included. (
http://www.phoenix-simulation.co.uk)
Of Course for the ultimate experience, it has to be the Level D 767. Untouchable although I am sure some would argue that the PMDG NG (737) & Queen Of The Skies (747) are as good, I just prefer the LDS 767.
Hope this helps,