Your requirements:

• I want to secure commercial transactions / to secure sensitive customer data
• I require the option of a customer confidence enhancing active site seal
  containing an embedded date / time stamp

We recommend that you use a GeoTrust Professional Level Certificate and choose a package such as QuickSSL Premium or True BusinessID which includes a bundled active site seal.

GeoTrust certificates are 128 / 256 bit single root SSL certificates. GeoTrust owns the root used to issue GeoTrust certificates and is already present in all popular browsers. GeoTrust issues highly trusted, Internationally accepted professional level and enterprise class certificates and are a highly respected and established WebTrust compliant security organization.

Click here to view the GeoTrust product page