Originally Posted by ependydad
Call your manufacturer first. Many will void your frame warranty because the king pin box isn't as beefy on a fifth wheel as it is in a gooseneck trailer. The claim is that the stresses are different and significantly higher with a gooseneck setup. I use a B&W Turnoverball gooseneck hitch and B&W's corresponding Companion Fifth Wheel hitch. Gives me the best of both worlds.
I was facing the same dilemma a few months ago. Most of the reading mentioned the possibility of voiding the frame warranty.
I ended up getting the same set up mentioned above. It had the best reviews for what I was looking for. It's worked great so far.