Map Chart with a radius around a zip code

[BuffaloGuy]

I would like to make a Map Chart of the US, and use the zip codes of individuals as points on the map. Then give each point a radius (50 - 100 miles) on the map to have a visual representation the coverage/overlap/gaps of the data.

I found a USPS list of zip code to Latitude/Longitude, which could make creating a radius easier, but I am new to Map Charts and I don't know if I am making this more difficult on myself.