their is a lot of solution.
First do a cluste with both http server. and your load balencer will distribute the load. that is the most effective and reliable solution
second use a tool like double take to replicate online data between servers. it acts like a cluster software but you can desable the failover feature so it will act juste for replicate the filse as soon as the files arrived
third write a script that will replicate your folders with robocopy or use viseversa you don’t need to script it it does avery thing for you. and you can sceduled it so it will replicate the folders avery 5 minutes if you want.
that all about it.
We use Replistor to replcate web server content between 8 web servers. Load balancing is done behind BigIP content switches. User uploaded data is not stored on the web server, it is redirected to a different server so there is only a single instance.