After reading other treads we decided yesterday to try Spanish Tax Forms Ltd. http://www.spanishtaxforms.co.uk/ we filled in the on line form and sent it off with in two hours John had emailed me the completed forms for myself and my wife.
Trusting me the to transfer the £ 24.95 to his account.
This cost me € 90.00 last year more than I had to pay tax.
Very professional and at a reasonable price.