Dropdown for Mainland OR Island Land In Land Search

Ok, We've needed this since private island owners could sell their land. Now, because of the private island price increase it is almost impossible to find mainland in the land search when looking to buy land. I only purchase mainland. Some people might only want private island land. Either way we need Private islands and mainland land sales in the drop down list when seaching for land to buy so we can isolate and display only the kind of land we are looking for.