HTML 5 Game & Facebook App - Pimp my Tank

We have developed a game using Flash in 2008 (www.pimpmytank.co.uk) we now need to redevelop the game in HTML 5 with far greater social ability. The branding can remain but company changed from Forces Insurance to Abacus.

We would like to get a Game Created using HTML 5. This should be used as follows:

1. Facebook App on our facebook Page - http://www.facebook.com/abacusinsurance
2. Dedicated Microsite - www.pimpmytank.co.uk

The main focus will be on sharing your pimped tank with your facebook friends or twitter friends and getting them to vote for your tank.

We want to run monthly contests against all entrants to give them something free (this will vary each month). We want to easily encourage those that enter the competition to share with friends throughout the month, displaying a live voting scores on the page and updating all those involved.

A person who wants to play has to like the "Abacus page" and perhaps even to vote? the more social we can get the better any ideas.

We are happy with the current functionality, layout etc.. but welcome recommendations for improvements.

This will be ongoing and therefore we need it setup in a way that is really easy for people to share, vote and take part.