Category Blog with meta keyword article filter Joomla 2.5

Hello I require a Joomla 2.5 Category Blog which is identical to the existing Joomla 2.5 Category Blog menu item except that it must be possible to filter the articles by meta keywords. In the existing Category Blog is an option where meta keywords can be defined. See attached screenshot. I want an extra tickbox there "Filter articles by meta keywords". If this tickbox is enabled then only articles which contain one or more of the meta keywords in the article meta keywords must be shown. All other functionality must be identical to the existing category Blog. This new menu type should be installable as a new menu type, not overwriting the existing Category Blog menu type. I looked at the code of joomla and think the task is not too hard, Basically one needs to add another condition to the item query to filter all articles for keywords. The logic of the meta keyword filtering can be taken from the "Filtered News" Module here [login to view URL] It has an option "Match Meta Keywords" The same logic is needed for Category Blog with meta keyword filter. I dont need exclusivity of source code. So the developer can sell also the code to others.