Theme recommendations please?

Hi folks, I am new to Gallery and looking for a little guidance please?

Using Gallery v2.3.1

I have looked at various themes and I like the Ajaxian layout, with thumbs sitting below the main image, but I would like the main image to change when a visitor mouses over the relevant thumb rather than having to click the thumb.

Can anyone suggest either :-
- a different theme that does this;
- a way to modify the Ajaxian theme to achieve this;
- another alternative that I haven't even thought of.

Suggestons from those with more experience would be greatly appreciated, thanks so much for your help

Thanks Dave,
but I don't see how that answers the question please?
Perhaps I wasn't sufficiently clear in my first post.
I want a theme that gives me the album contents presented as thumbs with the larger image of the first thumb above the set of thumbs, like Ajaxian does.
Instead of clicking the various thumbs to open them above in the larger image I would like the images to open when the mouse is passed over them (no click).(Image swap - Image restore with mouse-over)

If there is a way to achieve this by using a different theme for the root album as you suggest then I am all ears
thanks, Graham

Thanks, that points me in the right direction to try and setup the swap image effect.
Cheers,
Graham