68 Dart GT suspension upgrade recommendations - best bang for the buck

The car will be a casual driver. Car shows, occasional highway driving, etc. Always looking to spend the least amount possible but willing to invest where I need. Meaning if different shocks will have a noticeable impact, I'll start there. If the subframe connectors are a better improvement, I'll start there. Essentially looking to get a prioritized list and keep going down the list until the handling is 'good enough'.

With the wheels off the ground I feel no play anywhere right now.