Thanks for the feedback,
I posted a similar post onto the Vegas pro forums and somebody offered me a photoshop finished image all ready to drop into the timeline, its just a matter of working out the parent relationship and the composite, as I am going to be altering the plate colour to represent either night sight or IR, the problem is now finding how to crop the sight and animate it as though it is actually tracking the target, as I cant find a circle tool in the crop, just the pen tool, its kinda messy outlining the sights.
Thanks again,
Glenn