In my opinion, you should left justify the quotes, make the color of the quotes a dark body color, and then make the clients' names in the lovely shade of green.

When substantial text is centered, it does add emphasis, but it also reduces readability. When the entire page is centered, there's less readability but no gain in emphasis. And it is the same case, more or less, with color; a strong color is strong only in contrast to a more subtle color. The key is not to overload on strong elements (like alignment, text decoration, and odd fonts) while emphasizing which elements really need to stand out.

It does sound like a great idea!