The fuel tank in a V drive is in front of the engine. In my VTX it makes almost no difference if I have 10 gallons or 40 onboard. Looks like a sport Nautique only carries 28. Moving people to the side and observer seats works well, although the side to side balance is more noticeable than where they sit. Riding people in the bow at ski speeds is just nuts. While we do have a little more freeboard than a DD, it is a terrible place to have people if you need to spin quick for a downed rider.
As for bow weight - my stock front tank is 150lbs, and I run with it full when I am skiing. I've never skied a Sport Nautique, but a friend of mine sold his and bought a VTX after skiing behind mine - a sample size of 1 but he thought that the wakes were a lot better on the Malibu.
I am not suggesting you sell your boat - just that some of the suggestions for what works in my V-drive may not do the same thing in yours.