Download gallery or portfolio?

I’m starting a section of my website that is designed for downloads.

Basically, there will be lots of things for downloads (posters, fliers, brochures, banners etc), and about different things. Each of these will also have 2 or 3 different formats (such as .pdf and .ai).

I need either a plugin or a theme that displays a grid of images, and under each image will provide a link for .pdf download, and a link for .ai download. I also want to have a search function, which can search for tags across all types (so create a table of all banners, posters and fliers about the search term).

If anyone knows of anything that could help me, i would be much obliged ??