I am planning on putting either two 24 inch undercounter wine/beverage centers, side by side, or one 36 inch unit. The counter above will be walnut or possibly marble. Are there any issues with supporting the countertop over these? One of the KDs I spoke to said I either have to put a support between the two units if I choose the two 24 inch unite, and he would not recommend the 36 inch unit because he said that's too big a space to be unsupported. That doesn't make sense to me since the unit is intended to go under a counter, and I see pictures all the time of two 24 inch units side by side (subzero website for example). First KD said nothing about this, even with the two units (she didn't say we needed a support between the two). Anyone have experience with this? Thanks so much.