Hi Kevin,
At the least I would recommend a manual slider. I bought mine used off of CL for $150 bucks. It's a Reese 14K. It works great as long as you use it! I have a couple of small dents in the corners of the cab on my truck to show I didn't use it.
As far as the 5er you mentioned. I looked it up and see it has the corners of the trailer trimmed. That is a good thing for a short bed truck user. If I had to do over I probably would have bought an automatic slider. Yes they are heavy but they work as advertised.
Good luck, do your research well and let us know what you decide on.
John
