Most will start with the rear, and eventually get to the front forks....

Anything other than OEM will be an improvement... how much of an improvement you need, is very subjective.

There are many quality shocks out there. Not all the good shocks are very are over $1K.

I have tried several makes and several tricks, and I finally spent the money on a set of Ohlins. I didn't need the remote reservoir shocks, so went one model below. I paid less than $1K, more like $800. They are very good shocks, and I am satisfied.

Prior to the Ohlins, I bought the first Harley offering of SuperShox. They were a pretty good shock, and Brian has made many improvements as well as added several models for Harley since those first offerings.

Generally speaking (there are always exceptions), the more stroke the shock has, the better the ride should be.... So you may want to look into a 13" shock minimum...

Do your homework, listen to the recommendations, but eventually you'll need to put down some money and make your choice...

Good luck with your decision.