Use NearMap or EagleView for Hi-Res Imagery ($$$)
To create contours use USGS LIDAR and download a DEM of you subject tract. Then use QGIS (Free and a bit of a learning curve but well worth it) rster calculator to convert the DEM to feet. Next us the raster extraction tool to extract contours. Create labels if needed. Now you can export vector dxf, pdf or a raster image and import into Chief.
I'm new to Chief but have years of experience in GIS, CAD, and 3D modeling.
Links Below
https://qgis.org/en/site/forusers/download.html
https://apps.nationalmap.gov/lidar-explorer/#/
https://opensourceoptions.com/how-to-create-contour-lines-and-labels-with-qgis/
If you want to view your model in Google Earth Pro (Desktop) then export to Collada from CA and open in GE or import into Sketchup then export to GE.