Hi,
The only difficulty in your requirements is to transform those addresses in your Excel file to geo information (longitude/latitude). Fortunately, Google Maps API can provide geocoding services freely up tp 10k requests/day.
In my humble opinion, you would best of trying to do this yourself with Google Fusion Tables. You can upload the Excel File yourself, specify which columns are related to geographic information. Google API is automatically called to get geo points from addresses and then all this will be plotted on a Google Map and you'll even be able to generate a permalink to embed this in any site you wish.
No need to spend money on this. If you don't think you're up to it (but I doubt that, Google Fusion Tables is really straightforward), I could lend a hand if you wish.
Hope this helps.
Cheers