Assuming you have the pickup & not cab & chassis -
The 17 Ram pickup frame has a cross member, just under the bed above the rear axle that is made for installing a bolt in gooseneck hitch. See this link for a look at the cross member and how the hitch installs. “
https://www.youtube.com/watch?v=_MAZKpNIudA”
The Ram pickup frame is not straight, it kicks up over the rear axle. Additionally the top of the rear shock absorbers attach to brackets that are at the highest point on the frame and stick up another 1 1/2" or so.
Because of the aforementioned the flatbeds made by the manufactures that I looked at (Bradford, Hillsboro, CM & several others) sit farther above the frame then you would expect. Additionally they don’t make use of the Ram cross member for the bolt in gooseneck hitch. Instead the gooseneck hitch / receiver is built into their flatbed. Maybe not a big deal but I preferred my hitch attach to the truck frame as designed and not be attached to the flatbed that was attached to the frame.
In addition to gooseneck trailers I tow a 5th wheel a lot and got tired of climbing / leaning up and over the bed rail and then reaching in to hitch / unhitch the 5th wheel.
I wanted a flatbed as low as possible and utilizing the integral gooseneck hitch mount built as part of the Ram frame. Since I couldn't find what I looking for, about a year ago I had an aluminum flatbed built and installed on the 2017 in my signature. The deck sits a couple of inches closer to the frame than the off the shelf flatbeds, the fuel fill is under a hatch on the deck and the goose neck hitch sits in a well that is about 4" deep. Note B&W has a 1-2" taller version of their gooseneck ball.