Hi!
Here's a little mod that simply adds a "Search" button to Buy and Build mode. It looks through both the catalog name and description of objects.
It adds a little button on the catalog that looks like this:

Pressing it will prompt you to type in your search query.

Upon accepting, the catalog will be filtered by your search query!

Installation
Simply drop the package into your "Documents/Sims 3/Mods/Packages" folder.
Tuning
Inside of the package file you can find the Tuning XML. Only one setting is available for this mod, "kIncludeDescriptionsInSearch", which simply determines if the catalog description of objects should be taken into account when searching. Set to "True" by default.
Let me know how it goes, and if there are any improvements you'd like to see!