Hi @georgloesel
To get Owncloud 10.x on Ubuntu via “apt-get”, you can follow this page (to add the “10.0” release channel): https://download.owncloud.org/download/repositories/10.0/owncloud/
But you can also wait for the 10.0.2 version to be in the “stable” release channel (very soon). 
Regards,
Mickaël