You can use command line switches and alias shortcuts, but it gets complicated very fast.
Since the OP likes to use AppleScript he can probably handle it.
You could use the --user-data-dir= switch to Opera to use an alternative profile directory, e.g.:
do shell script "open -a /Applications/Opera.app --args --user-data-dir=$HOME/Library/Application\\ Support/opera_alternative_profile"
Just change the last part (opera_alternative_profile) to whatever you consider to be suitable.