Thanks for your replies.
I already took a look into that topic, but it seems to me that it's quite a hassle to get the HUD working in the another company F-16 and that it's still not working perfectly at all. Besides that, the another company F-16 has it's own, perfectly fitting, unique HUD. I don't want to lose that, as it's part of the software I paid for at another company and it works good.

The real question here is: is it possible to use Captain Sim Weapon without the HUD that comes with it?

By the way, I noticed people who try to use Weapon with old warbirds, like the spitfire. It isn't actually realistic at all to install the CS HUD into those aircraft, so I guess it should be possible to use Weapon without its HUD?