With either one, your cabinets, flooring, paint will all need to coordinate.

Waterfall counters look best in very sleek/modern kitchens. You might want to reconsider if you have an average suburban house.

Can't vote without knowing anything about the kitchen these counters will be going in. You might want to search on the forums as many of the complaints about quartz seem to be with products from MSI.

Hi! Our house is a new build and will be modern. Thanks for the heads up about MSI!

The second appears to be a quartzite. I prefer natural stones - however, you need to receive a sample of the quartzite in order to test it out re: stains. If it passes the test, it would look better in a modern home with a waterfall than the MSI Quartz. You will need more slabs in order to match the veining that will run from the top of the island down the sides of the waterfall.

Are you planning on running the quartzite up the wall as your backsplash? That would work well in a modern style kitchen. Plus, it's difficult to select a tile that works well with that quartzite in a modern kitchen.

Are you building a custom home (where you select everything - including the land where you will build your house)? Or - is this a semi-custom home or a tract home (builder doesn't allow many decisions or changes). Is there a model home that you've toured? If yes, will you post photos of the kitchen?

Please post the type of cabinets/floors that you plan to use in the kitchen. That will provide us with the information we need to give better opinions/suggestions.

The Lamberti Bianco looks similar to the Florida Wave quartzite I considered from MSI. The sample performed well. I like the striations in the Lamberti, but you need to consider where your seams will go and the difficulty of lining up the waterfall edges, any countertop corners, and any corners in your backsplash. Ditto for the Versailles.

The Calacatta Versailles, being quartz, could scorch behind your range / cooktop, so you want to be cautious about that for a backsplash. (You can find posts here of folks who have had that happen.)

Either one could make beautiful counters. Be sure to bring home samples to view with your cabinet samples and flooring, and do some tests (here's an article with some info.) If doing a waterfall, you'll want to make sure you have an excellent fabricator with experience doing waterfall edges. You'll also want to be involved in the templating process if you care about lining up the patterns.