Canonical or noindex for PPC landing pages?

[designquotes]

I have two pages for this example.

http://www.designquotes.com.au/web-design-quotes/

http://www.designquotes.com.au/web-design-quotes-melbourne/

The first URL is an SEO optimised page.

The second URL is 99% the same, except that it specifies a city. It's intended use of for a PPC campaign.

The first page has major cities mentioned on the page so I don't have to build a separate page for every city variation.

The second URL is designed to be city specific for a geographically targeted PPC campaign. The more specific, the higher the conversion rate.

Should the second page (the PPC landing page) use a canonical URL (since it's 99% the same) or should it be noindex?

[David_ODonnell]

I think you should implement meta noindex to prevent duplicate content issues.