I'm not and expert but here it goes.
Over all I like it. As far as
SEO goes I'm not sure what else could be done other then maybe titles on the text links but this is more for accessibility.
Other then that I think the page could be made about 50px wider. This way it will still show on a 800X600 res without a scroll bar but also use up more of the screen on a higher res. I like the images you used but feel they maybe a little to big as they seem to dwarf the words in the center. Lastly I would move the phone number down into the Green area and slide the whole page up. The off white top looks out of place to me because of the amount of off white.
I'm not sure if this info is available to you but I would have liked to have seen some of their work. Also a list and images of the different types of products / styles of hats and shirts with color choices that are available through the site.
Note
Misspelling on pricing.php "per teh packaging"