2004 SAN 210 Ballast

I have 2004 210 SAN Team I currently run stock ballast, I was looking at adding more weight but was not sure if I should just replace the hard tanks with the V-Drive Fly High Pro-X sacs and hard plum them in or add the wedge sacks on top of the existing tanks. Has anyone plumed in the Pro-X sacks? What added parts would I need to purchase? Has any one connected the Pro-X wedge sacks to the hard tanks so to can fill both with the same pump?

Thanks