I am notsure,but you can try this.
First copy all files to server2 from server1 and always to copy file to both server.Make server1 as base system from where you can admin.
Admin is always with www.store1.com/adminurl.You need sync files from server1 to server2 and need share same db server.
On second server server2, for run server2 you need to change at index.php
Mage::run($mageRunCode, $mageRunType);
to
Mage::run('SECOND_SERVER_CODE', 'store');
/* it will store_view/store/website be depends on configuration */
NOte: System>configuration all scope you need set url store base secure
and unsecure url,media,skin,js url should be store1 url.Only need to change
those store2 scope.
This make all file upload at server1.