Did you ever consider going with WorldPay instead? That's what I did after seeing the ridiculous measures you need to go through to get a merchant account.
I'm whining about my problems because I know countless others have had the same issue. I want to incite discussion on what problems people should expect to face and how they can go about it. So others can learn.
However, I think we had the issue that Lloyds Cardnet wouldn't play nice with SagePay as it didn't do 3D-Secure. I could be wrong though.
And thank you for your offer. :)