Bolt on shocks or cushioned equalizers for travel trailer?

None.

Leave well enough alone.

Extra parts to break.

Have a "handling issue"?

If so, look elsewhere, trailer does not "need" shocks or special parts for best towing and handling provided you have correct tongue weight to trailer weight ratio.

10%-15% tongue weight, run it up to the max of 15% and trailer will handle plenty fine without extra parts that can let you down.