Trying to make a copy of a live site

Hi, I am trying to set up a test environment alongside our live wpmu site.
I was hoping to be able to copy the live site onto a test server, full site contents and all 265 databases, but I admit, I am struggling a bit in the dark here.

Here is our live site: http://mediajungle.dk
And here the test environment: http://udv.mediajungle.dk

Obviously, the move was never going to work straight away with key settings in the copied site not configured right for the new test site URL.

So for the new test site I inserted these two lines into the theme functions.php file (BP Social):
update_option('siteurl','http://udv.mediajungle.dk');
update_option('home','http://udv.mediajungle.dk');

And I changed this line in config.php from:
define( 'DOMAIN_CURRENT_SITE', 'mediajungle.dk' );
to:
define( 'DOMAIN_CURRENT_SITE', 'udv.mediajungle.dk' );

Now, the front end works on the new test site, but only when I comment out these lines in config.php:
define( 'MULTISITE', true );
define( 'SUBDOMAIN_INSTALL', true );
define( 'SUNRISE', 'on' );

as soon as these lines are left in, the new test site URL just re-directs to the live site.

And when I try to access the dashboard on the test site, I get the white screen ...

I know, I know - in over my head ... But I was hoping that some one could give me a hint as to what other settings I need to adjust in order to get the copy site up and running.

Regards
Kristian