My only concern would be expansion/contraction of the bed liner vs the plastic. I did pop up camper top with a bed liner and the heat of the sun caused the bed liner or plastic camper top to expand/contract at different rates and it cracked and pealed the entire top. I am sure others have done it.
Oh I have 3 Highland skulls from two different steers and a heifer we had. I have have studied putting on of them on the front and putting the front camera out of a nostril.
I say get some Boss Hog Horns!! Overall looks great.