Employer branding is not that difficult so that you need to hire services of external consultant. Secondly "branding", whether it is employer branding or product branding, does not have "end" as such. You have used typical HR jargon of "end to end" service while soliciting services of the consulting organisation. Branding cannot be placed at par with recruitment services to get "end to end" services.
I recommend you reading books on branding. Of course employer branding has nothing to do with product branding, nevertheless, unless you understand the basic concept of branding, you will not be able to develop right frame of mind. To succeed in employer branding, first your systems and processes need to be stabilised. Employer branding also depends on the organisational maturity. Employer branding also depends on the various organisational surveys like "Employee Satisfaction Survey" (ESS) etc.
Employer branding depends on how the organisation treats its people. Just yesterday, there was post about prominent American MNC for the worst treatment and illegal termination. Click the following link to refer it:
Today's world is of social media. The lesson all HR should learn from the above post is that social media helps in undercutting the strength of the brand as well. Social media is nothing but the mirror of the organisational affairs.
Almost six years ago, I had written article titled "Role of HR in Brand Management". Click on the hyperlink to refer the article.
To improve your awareness further on this subject, you may go through the following link of Citehr:
Last but not the least, have you spoken with your Head Marketing on "employer branding". He/she is the first person to give you suggestion/advice. What are his/her suggestions?