Do your clients absolutely need editing online editing capabilities? Are your files that you are pushing out extremely large? If not I would completely avoid setting up a GIS server at all and get your feet wet with an open source mapping library such as leaflet. We have successfully created a county-wide parcel viewer using Leaflet hosted alongside our normal website, no GIS server at all (20k parcels). We also host infrastructure viewers for small municipalities - where the shapefiles (geojson really) are at max 6mb in size. Some of the pages are secured using normal apache htaccess (using cpanel, no coding needed). If you do not need password protection - which may violate public records laws depending on your state - you could host a site like this for free on github, surge.sh, openshift, etc. I think surge.sh allows for passwords on their paid platform.
If you do have large files you can do some simplification via ArcMap or mapshaper to see if that helps.
Examples
https://www.ovrdc.org/apps/wellston/
https://www.ovrdc.org/apps/geojson-tiles.html