Can i sell Head Texture + The Texture?

.... yes

Use the art section above the market section to sell art and you can either put the texture item up for sale at the official market, or sell it in the market thread.

You could leave the texture on the item and sell it that way, if that's what your asking.

It's advised that you sell the texture and the item separately to avoid complications.

And also be sure that the texture on the head texture item belongs to you.