Finally finishing my basement up and want to expand my home gym equipment but need ideas on what I should get.

What I have:

Nice Body-Solid Cable Crossover setup
Assorted dumbbells
Incline & Decline benches
Roman chair
Treadmill

Severely lacking lower body type equipment. Could use recommendations for this and whatever else anyone thinks is needed. Also could use help setting up a leg workout program (currently not doing anything lower body)

Thanks in advance