Modular Home HVAC & Plumbing Design

I need a comprehensive design for duct work, HVAC sizing, and plumbing drawings for a modular home. Requirements: - Duct work design for central air conditioning covering the whole house - HVAC sizing... (Budget: $250 - $750 USD, Jobs: AutoCAD, Building Architecture, CAD/CAM, HVAC, Mechanical Design, Mechanical Engineering, Plumbing, Product Design)