I was browsing viperpits and i saw a project for a physical HUD i should have enough knowledge about the optic part, does someone knows where i can find accurate measures for the box and the collimation glass? Many thanks in advance.

Go here: http://www.mikesflightdeck.com/

You'll be a happy man.

g.

Thanks is there any place where i can find details on the real F16 or F18 HUD hardware to build a mockup?

I don't know about the F/A-18 (I think it uses two combiner glasses like the F-15 HUD does), but you can find out tons at http://www.viperpits.org - they're total F-16 nuts over there.

g.

For the F16 try also http://www.xflight.de/