Looking for an alternative to Dropbox since we have roughly 40+ people with devices, inside and outside the domain that require access to pdf's. Committing ourselves to Dropbox will run us roughly $600 a month. I've toyed with the idea of a NAS dual-homed inside and outside of our firewall. I've yet to find an of-the-shelf solution. Remote access is required for iPads and Windows laptops, Android would be nice but not mandatory. Internal access is primarily Windows. Any input welcome.