Daz,
If you're just after the DIN panel, I recall Alan Zini from Dragon saying (on Yahoogroups) that he does a panel with 43mm holes that are easily expandable to take the 46mm HKS gauges that fits below (or above) the radio. I saw one when I was last up there, and I believe that they aren't very expensive at all.
I decided to mount my boost gauge in the LH central air vent as I didn't want drill holes in the surrounding dash, or an A-pillar pod, but to still retain visibility whilst driving.
HTH
Geffers