Hi Andy,
I'm glad my reply help you!!
You might not be aware of this, and I only found it out yesterday but if you want to setup a site on your new VPS and get it all up and running before pointing the DNS to it just do the following:-
1. Add the new domain to your new VPS.
2. Setup all it's hosting settings / limits / ftp users etc.
3. Copy all the files accross using ftp (or the CPanel file manager).
4. Setup any databases you need.
Ok, so how do we now test that the site is actually running from "the outside world"? Simple, just type:
http://hosted_ip_address/~account_username/
For example if your domain was sound-designs.co.uk, the username for that account was sounds and the domain was hosted on ip 11.22.33.44 you'd type:-
http://11.22.33.44/~sounds/ Hey presto! sound-designs.co.uk should be displayed.
You can now use this address to fully check the functionality of the site before you set the DNS to point to the new VPS. Oh, I should point out that this probably only works if your new VPS is using CPanel although I'm sure there's a similar way of doing it on Plesk.
Hope this helps!