What paperwork do I send with the SVA application?

£150 bits of paperwork....

You need form SVA1 which can be downloaded here:

http://www.vosa.gov.uk/vosa/carlgvowners/importingandbuildingvehicles/applyingforasinglevehicleapprovaltest.htm

Click on the pdf download, save a copy to disc and print it off.

You could instead write to your local DVLA to ask for all the relevent documentation for SVA and registering.
This is what I did, the DVLA chap sent me all the relevent bumph, but better still I then had is direct phone number, which was extremely useful when wading through all the red tape. He was extremely helpful, and saved me alot of time, he was also the guy who inspected my car for registration.

Best of luck,

Dave

Oh and don't forget the small matter of the £150 cheque
Cheers

Dave

Hells teeth, another senior moment.
I see you have already got the application.

As Muzchap said.

Dave.