Searching through nodes and outputting the details on gmap
Does it have to be a search box? If not, use GMAP's Views integration and create exposed filters for the fields you want to filter by. Instead of a search box, use a dropdown for bedrooms, city, and whatever other filterable fields you include. 

Using a text input/search box may cause usability issues. You can't account for the variety of keywords a user may input, nor will you be able to filter appropriately for unknown terms. Giving the user defined filters (which they are familiar with) will be much easier for them to understand and use.

Better Exposed Filters may come in handy here depending on what type of filters you use -> http://drupal.org/project/better_exposed_filters