possible yes. Easy no. There is an (unaffiliated) project to document and provide some additional code for custom server installs here:
http://git.27o.de/dataserver/about/Installation-Instructions-for-Debian-Wheezy.md

Note that a) you can buy additional storage, which will be by far the easiest and also support zotero development and b) you can use webDAV storage, available from multiple third party providers, to sync attachments in your personal Zotero library:
https://www.zotero.org/support/sync#file_syncing

Notes are synced for free via zotero. The 300mb limit only applies to attachments