I have several threads and tons of pictures, video on the Mojo with Flow that I have done over the last two summers. I am actually going to be uploading more today.

I will not say that the 1100s won't work, but in my testing from 650s all the way to 1500 rears, the 900 perform the best.
You also need to be careful because if you over weight the rear of the boat the Flow will not work, it will just flow and wash out everything.

This is also only true on the Regular side, if you are surfing goofy then its a whole other setup to get the best wave.

If you are not running a Flow, then more weight on Surf side only is always better.

You absolutely need the IBS for a decent Mojo wave. We run nearly 1700-1900 in the nose due to hard tank, IBS, 450 bag on seat and 1 or 2 adults in the nose.