How much for custom trim piece?

I just purchased a Pioneer AVIC-Z1 for my 2003 Honda Pilot EX.  There is only one problem.  The double din dash opening is a bit larger than the standard 4X7.  I need a custom trim piece to cover the gaps but I don't know how to make one and nobody currently makes one.  The deck mounts directly to the factory bracket so mounting is not an issue.  All I need is something to cover the gaps.  Another slight problem is that the OEM deck has some curvature to it so I would need a trim piece that curves along with the rest of the surrounding pieces.  How much would I be looking at spending for this custom trim?  Can somebody here do it and make it look the same color and texture as the rest of the black plastic in the area.  It doesn't seem like that big of a job but I wouldn't know since I've never done it.  Here's an "paint" example of how big the gaps are and also an example of what I need it to look like.