I would like to make a custom sign(or poster) I would like to just put a simple name on it, is this possable?

You get a copy of the texture that is used on the poster object you want to use. You then edit the texture to your liking. In the GECK, you create a new texture set object and attach your texture to it. You then copy the poster object and make it a new object name. And then apply the texture set you made to the copy of the poster object.

Easy, right?