These pics give you an idea of how it can lay out. You won't get much more than 400# under the seat no matter how you do it.
If it was me, I' put a bag in the ski locker too. When you aren't doing slalom, fill the bag and put the skis on the floor behind / beside the driver seat. Then you get 800# in theback and the only thing on the floor is the skis. You could also put the skis in a tower rack if you have a tower.
You will probably be fine with 400# in the rear and 400# up front. It might not be exactly as big as you want, but you could have a decent wake while still having storage space. If you find it isn't enough, put the skis on the floor and a bag in the ski locker.
Thanks for those pics! That saves me these extra couple of weeks before I could get to my boat and pull that seat out to really investigate. I think you've convinced me to just go with sacs, I'm leaning towards that 400# tube under the seat and around 400# up front as well. By the end of the season I was only running 660# alongside the engine cover and that was plenty for me, any more weight than that just seemed like splitting hairs so 800 spread out like that should be great. My problem now is purchasing the fly high bags and not spending too much money. Right now I have 4 launch pad bags and frickin FIVE pumps, all used, that I will be able to sell but I still don't know that by the time I integrate all of the new stuff I will be able to come out without too much damage to the wallet.
If you know of anyone in the market for 2 330# bags, 2 440# bags, and/or 5 pumps let me know!!! Thanks for the help.
Bulging isn't a big issue as long as you watch it. Overfilling the bag can cause some bulging that would push up the cushions a bit.
If that link doesn't work out for you post a wanted ad here and on the Moomba forums. Like I said, that is a standard bag Skier's Choice uses in Moombas and Supras and people commonly look to upgrade to bigger ones and sell their original.