We will have the following:
FIrst, we determine the volume of water each bead will have:

Now, we also know that the density of water is approximately 1000kg/m^3; so we determine the mass of water each bed would have:

Now, using this mass we determine the force it would apply on the floor:


So, the force the water bed would apply on the floor is greater than the limit the floor can withstand. So, CNM should not make the purchase.