Searchable Google Map Wordpress Integration/Plugin

I am looking for a way in use my existing Google Maps in my Wordpress website - but allowing visiting to select which map to display (or overlap a number) - by choosing from a selection of options (configured in the back-end of the website).

The user should also be able to enter a postcode to be shown their location, overlayed with the markers on the map(s) selected (by checkbox) - in order to find the nearest group to their location.

Ideally I would like the front-end to be made up of three elements:
1. 100% width along the top of the map - a text field for entering the postcode and "SEARCH" button
2. down the left hand side (approxiately 30%)- a check box selection of the available maps (configured in the back-end)
3. on the right hand side (70%) the Google Map screen, which automatically changes when Maps are selected/deselected.

Behind the scenes should be quite straightforward:
- identify Google Map(s) users can access (the name of this map should then be displayed as a checkbox option on the front page).
- Have the ability to set up mutliple instances (with different maps available in each) - with a shortcode generated so as to be able to insert the correct searchable map on appropriate pages.

My guess is that this will need to be writtten as a plugin to enable it to integrate with Wordpress.

Look forward to hearing from you if you think you have the answer!