First off - CONGRATS on your first client!! Way to go.
Secondly, to answer your question, the free contract on this site should be quite sufficient in conjunction with a confidentiality agreement. (Given the nature of what we do, a confidentiality is very important.)
My service agreement is a mixture of info from the VAF contract
and a contract I have used in the past with other service businesses. I choose to have everything in one agreement (contract and confidentiality agreement).
Hope this helps,