If you want to acauire 'surface data' get vectors (contours, points) or LiDAR to use in your your surface definition. You may also use raster data such as geotiff and DEM. You won't be able to use a WMS connection to create a surface. You can get free LiDAR and topographic contours in shapefile format from The National Map (TNM). To download, visit the site >>HERE<<.
Image-1. Topo contours in shapefile formal
Image-2. LiDAR data.
NOTES:
If you want to build a surface showing a river, the adjacent riverbank and surrounding parcels of a newly newly built residential development, then free downloadable data may suffice. If, however, you want to create a surface of a single parcel showing the backyard patio, front yard, street frontage, and culvert running under the driveway, then these types of downloads may not work because you can't expect a high level of detail to be present in free data. Don't be fooled, free data will never be a substitute for survey data collected in the field.
For images you try earthexplorer.usgs.gov which BTW, I have never liked. The best imagery is not free. Bing aerial imagery is the closest you can get to free, adequate resolution imagery. For really good images, you'll need to purchase a third party add-on or subscribe to a service.
Chicagolooper
