Marketing postcard design required

I own a firm of accountants (www.yorkshireaccountancy.co.uk) and need a postcard to send to prospective clients. Needs to be exciting, innovative and most importantly make us stand out from the crowd.

I can provide logo and basic ideas.

I use www.imail.co.uk to send these so we shall have to ensure that the postcard fits in with their basic criteria (space for address etc). Again this can be discussed further if required.