The CPO costs the dealer around $3k as I recall.
You need a third party pre purchase inspection (PPI). Find a good indy or take it to another dealership not owned by the same group as the selling dealership.
Arming yourself with a PPI will help you negotiate a better price if they find something.
Know that boxster prices are literally all over the place, and there's piles of them for sale all over the country. Don't fall in love with just the one you're looking at right now... you may find one with more options, a year or two younger, and for the same price in California... which is worth a drive or the $1000 to ship it to you.
The 07 S's have a 3.4 in them vs. the 3.2... you may want to at least drive one before you settle on the 05S.
The options are perfect though... exactly what I would go for anyway!
Do post pics of whatever you buy. These shopping days are fun. Savor the moments!