Depending on the quantity of devices you might want to consider using an EMM to help with managing your applications and devices. Zebra's partner page to find EMMs is Mobile Device Management Solutions | Zebra
To use StageNow, Ian has a number of posts to use a centralized FTP server (the most recent one is here: Third (and last!) Revised method for deploying StageNow profiles to a remote FTP server )
Do those & Ian's earlier posts meet your needs?
You're really going to want to use an EMM for APK distribution if the devices are in remote locations. StageNow can be effective but it was never designed to be an EMM.