I don't think that is the one. Here is a link to fly high's page and go down to the X2 additional ballast there is part #'s there and just send Ian @ onlyinboards a email with the #'s and he should be able to get you set up. I think the # is for the kit with the valves so it will be like 1100 I think. Just tell him you want the sacks from that kit. Here is a link that shows how to install and all the addition parts you will need.
http://fatsac.servehttp.com/FlyHigh/FlyHighSacs.html http://www.mastercraft.com/teamtalk/showthread.php?t=25491&highlight=high+ballast Sorry I didn't get out this weekend due to the wind and now bad flooding of the river so it may be a few weeks before I can get any pics.
rzap how many people do you have in your boat when you surf? Any pics of that wake? To me the pocket is good but I am no pro. I might have to try a sac on the seat to see if there is that much of a difference. I have one but don't want to mess with extra sacks and pumps if I don't need to.