If you are going to weld one up , if you can still change your mind on the gooseneck head, Atwood makes one that is completely different than all the regular gooseneck couplers. You don't have to get right under the thing like a bumper pull ball, but you actually back into the thing like a 5th wheel hitch . it you have about a 5" wide to play with to line up the ball and just back it under.
I bought a carhauler with one and now I'm going to get one of the couplers and have it rigged to my gooseneck adapter that is on my 5er. Saves a ton of headache hooking up
The coupler is #75025 and the coupler with the upright post is75401
Best of both worlds the ease of a 5th wheel to hitch up and the extra articulation of a gooseneck to keep everything out of a bind