Comprehensive Landscape Plan for Duplex

I need a detailed landscape plan for a block where a duplex will be built. The plan should include:

- Pads for the duplex
- Retaining walls
- Excavation plan with drainage

Additionally, I require a 3D visualization of the landscape plan.

Please also incorporate specific materials for pathways or walls as per my preferences.

Ideal skills and experience:
- Landscape architecture
- Experience with drainage and excavation planning
- Proficiency in 3D visualization
- Knowledge of various materials for pathways and walls