That's pretty much the way I rode one this weekend. Didn't have the bow ballast, but we put two side sacs and a tube sac in the front (should be about the same) One 150 on each side in the back, and two people in the boat, wedge down. Sure you can get it bigger, by putting bigger sacks in the back.
.. I rode that way about three weeks ago.
It was bigger than Attila's slammed X1.
... Sorry buddy, but it was.