Thanks all for the advice -- I'm probably going to go with the GIII after numerous recommendations from people both here and elsewhere. Tyre shopping certainly doesn't suffer from lack of variety...

rubbish. ive worked in ford service and seen every XR we service do at least 30000km to them, and anything under 50000 out of them was due to dodgy wheel allignment

One should hope so -- 10,000km's out of a set of tyres would start to become an expensive exercise at ~$1000 for a set.

Had the GIII's fitted yesterday and so far are quite happy with them; much quieter than the Dunlops used to be, will wait till they wear in a bit before testing them for grip!

Just be a bit careful with tyre sizes.
I have a BA XT and I got some second hand 17" wheels with 245s on them and I found that the speedo was way out. I was nearly doing 120 which was 110 true.
I now have 50 series tyres on the car and the speedo is only fractionally fast now.
Check out the follwing web site which lets you compare tyre sizes:
http://www.miata.net/garage/tirecalc.html

Tyres have a code system moulded into their sidewall that allows you to understand
their technical capabilities.
This code provides information on the tyre’s construction (eg radial), its size, its load
carrying capacity and speed rating. The two main codes in Australia are metric and
eurometric systems. The following example is for a passenger car with the metric
code system:
P195/65R14 87H
• P indicates the tyre is a passenger car tyre.
• 195 indicates the nominal section width of the tyre in millimetres
(195mm).
• 65 indicates the aspect ratio. Ie a comparison of the tyre’s section
height with its section width (65 indicates the height is 65% of its width).
• R indicates radial ply construction.
• 14 indicates the nominal diameter of the wheel rim (14 inches).
• 87H is one of different codes which indicates maximum load capacity
and speed at which tyre can be operated safely. These codes are
shown in manufacturer data or in the Tyre Standard Manual by the Tyre
and Rim Association of Australia.

this might help some people.
http://www.toyo.com.au/TechInfoPDFs/Alt ... ations.pdf