Don't sweat your bench too much, it isn't too bad in comparison to your squat. However, your squat is lagging way behind your deadlift.
Have you truly maximised linear gains? I think you could add a lot more on your squat and bench before doing a slower program like 5/3/1.
If you have, then Boring But Big is the most popular accessory system and works really well. I would just do normal 5/3/1 and BBB.