Yes you need a slider, 88 degree is not as sharp as you would think and you will have to slide the hitch back to get into some tight campsites and even some gas stations.
Avoid brands that have steel sliding on steel, you have to put the fifth jacks down to slide the hitch and many times disconnect completely which is a pain.
Reese makes a nice roller type that you can slide with the fifth wheel weight still on it.
You can spend a lot more and get an electric slider or even one that slides automatically as you turn but those are overkill for the average weekend camper.
Do not try to get away with a cheaper fixed hitch...you will take out your rear window sooner rather than later.