We downsized in 2004 from a 26' MH to a truck camper. We are both in our early 70's and it's a bit small plus climbing those steps, so we are considering the shortest 5th wheel available. I have a 2...
If you get a small FW, it may not tow level with the 250. I would get a small TT, or a 25' FW. With the FW hitched over the axle, a 25' would not be much longer, behind the truck, than a 20' TT.
A longer trailer is easier to back, than a short one.