Concrete Block Retaining Wall Design

I would like a quote for a full design package for a concrete-block retaining wall that will stabilise a gently sloped backyard. The wall only has to hold back less than 4 ft of soil, but I still want it engineered correctly so that it lasts and meets local code.

Please include:
• Layout and dimensioned plan/elevation drawings ready for a contractor to follow
• Basic structural calculations showing sliding, overturning, and bearing checks for a gravity wall made from standard hollow concrete blocks, plus any reinforcing or geogrid if required
• Drainage and back-fill specifications (filter fabric, perforated pipe, weep holes, gravel zone) to keep hydrostatic pressure under control
• A concise materials list so I can price the blocks, cap units, aggregate, and drainage components locally

I’ll supply site photos, a rough hand sketch with spot levels, and soil type once we start. If you prefer software like AutoCAD, SketchUp, or Revit for the drawings, just let me know—DWG or PDF output both work for me. My main acceptance criteria are clear buildable drawings and calculations that demonstrate the wall’s stability for its intended height and soil conditions.