What are my options if the version of PHP packaged with Debian Wheezy is too old and I want to run something newer? Besides switching to Ubuntu stable or running Debian Jessie (not great for production), is there a way to only install the new version of php and continue to receive package updates for it?
Under ubuntu, Ondřej Surý maintains a PPA with always up-to-date PHP version with modules and extensions. Hope this will be usefull.
you should be able to just add the newest packagelist.
Edit the sourcelist:
sudo nano /etc/apt/sources.list
Add the packages to the end of the list:
deb http://packages.dotdeb.org wheezy-php55 all deb-src http://packages.dotdeb.org wheezy-php55 all
Update the system:
sudo apt-get update