Wiring for a spa (240v)

I think I bought the wrong spa disconnect panel. I picked up this one: http://www.connecticut-electric.com/spa.asp
It appears that the GFCI only protects the 120 volt branch circuit. It is rated for 20 amps/125 volts.
I liked the idea of the additional 120 volt leg as I can use it to supply power to the shed I am going to build. But I need GFCI protection for the spa.
Can I just use a GFCI breaker in the main panel to power the spa panel? Or does the fact that the spa panel, which already has a GFCI in it, negate that route?
Basically, I am asking if it is OK to have 2 GFCIs on one circuit? I want to use the d/c panel if I can, if not, I'll get another.
TIA

 

Looking at the blue label on the website it says:
"240 GFCI Protection" The text on the gfi says "20 amps (min) through 50 amps (max)".
I am starting to think it may be the correct one afterall.

 

That disconnect looks fine. It says right on the front that its rated for 50amp 240v. And in the picture it has an extra 15 amp breaker for a branch circuit.

 

Thanks for the reply. I didn't want to mount/install it with those questions in my mind.