How do you optimize my server for server file downloads, aside from purchasing a quicker network plan? The files are static and saved inside a folder out of the box. An .htaccess file guarantees files have to download instead of make an effort to open in browser. Could it be suggested to utilize a CDN?

A CDN is certainly a method to get good performance, however the cost only is sensible for quite large volumes.

What type of files are you currently serving? If they are compressible (eg HTML, word processor documents, Ebooks not JPEGs), then make certain compression is enabled - use mod_deflate.