Well according to your manual, it says to use this one specifically. Now I don't doubt at all that it would work with other adapters though, but if you want something 100% sure fire, that is it.
However, I have no idea how you could fit a barlow in there. Personally on mine, I only use that style adapter for when I was shooting without a barlow, and anytime I was shooting with a barlow, I was just using my ZWO ASI120 which just slides into a 1.25" eyepiece hole.
If you want to use a barlow with it, I suggest going with what yawg said and just get a normal one. The only reason I didn't suggest is because I remember reading someone having an issue over it. He knows more than me though so I'd trust his suggestion.