Yeah I wouldn't select any additional strake options. The only option you have is if you want them sealed or not. If you are on salt water go sealed. I have the sealed which are pictured above.
Sounds like a bug on the website, only that never happens.
That was a sarcastic comment, in case anyone was wondering. The Bennington website is notorious for bugs.
Far as I know, you can add strakes to the base 2-tube package, the outer tubes on the Express, and to the twin Elipticals. I'm quite certain SPS and ESP are not modifiable.