displaying images and thumbnails in node

I've tried possibly every image module out there, to accomplish something rather simple;
I want to add multiple images to a node, which are automatically shown as thumbnails and one large size image above. When a visitor clicks on one of the thumbnails, it replaces the large image with the image that corresponds to the thumbnail.
Here's how I want it to look like: http://www.roderickhietbrink.nl/html2/groen.html

The Galleria module came very close, but it does not generate thumbnails (but rather scales down the original on the fly) which causes a lot of issues in my case.

If there's anyone with an idea (perhaps theming a certain node type using php?) suggestions would be very welcome.
And uhm, I'm not all too familiar with php...

thanks.