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1. Number of searches made for each keyphrase
2. Number of results (competing pages) that exist.
I would say if one term has a lot more searches made on it and doesn't have many more results than the other go for that one. But, often times it can be a hard decision as to which side you want to go for. You may have to decide how hard you want to work on SEOing your website and how valuable the "titanium" targetting is worth.
I cant create duplicate pages with the keywords switched.
They needn't be duplicate pages .... you could create pages that were quite different in content, one optimized for one term and the other optimized for the other, and both useful to your visitors.
However, it is indeed possible to have the same page rank well for more than one phrase. I know someone whose PR 6 home page shows up in Google's top three for several phrases in the pattern of "elegant widgets", "classy widgets" and "upscale widgets". The page's main SEO focus is the busiest phrase, and the other adjectives are woven into the body text, attributes, etc.. Inbound link text includes an assortment of "widgets" phrases, as well as the company name, domain name, etc.. The page ranked well both before and after Florida.
I'd call the category moderately competitive; it's a big-dollar industry with a few SEOs who clearly know what they're doing, but there's little or no affiliate activity to clog up the SERPs.