A three second animated video introduction from design I will supply

My client is a start up business on a budget and wants a short intro and ending designed for their videos on Youtube. I'm a graphic designer and can come up with the creative stills in a storyboard and supply Photoshop /Illustrator image files but I need it animated in a format that they will be able to edit into their videos. It only needs to be three seconds long at the start and the same at the end. If you take a look at Nigel Botterill's youtube channel - search for 'Nigel Botterill NBTV Ident' , that will give you an idea of the length and simplicity although what I'm looking for is more 2D-looking animation.

As a rough outline there will be an animated 'cooking pot' walking from distance into foreground with the sun rising out of it when it takes its lid off as if doffing/tipping its hat. The lead out will be the sun setting - fade out to dark with the business strapline, then the web address.

I need some guidance on what I need to provide you to make it work smoothly.

I'm not sure what it needs to be made in - Flash and After Effects possibly?

Can you let me know how long you'd expect this to take, too.

Many thanks