Imo, find a product you like first and use the in-house contractor who is held accountable to someone other than yourself and the CSLB. (When a problem occurs, the CSLB is often too overwhelmed to take initiative and will rely on you. My last contractor was licensed but his trades were not. The CSLB said they would set up a sting but I had to take the time to assist.) Decide if you want pre-fab, semi-custom or custom. It could be a large price discrepancy but choose based on what your priorities are. In my experience, contractors will try to talk up the benefits of going with whatever gives them the larger profit margin, especially if it's something they build themselves. I prefer products that don't have a lot of field adjustment to be made. I'm a perfectionist and want as much done in the factory as possible. I personally find too many drawbacks with travertine to consider it for use in my home. Just be aware that the stone naturally looks like Swiss cheese. The holes are filled with resin and will eventually come loose. Ask anyone who installed it in 2006 when it was the flavor of the month. Learn about the various materials pros / cons so you don't get taken advantage of. Go to some stores and pick up some catalogues and take some samples of the materials. (I just did stain and durability tests on my own using various counter top sample materials: Corian vs. Quartz. It helped me form a decision.) Talk to someone who does not work on commission for the feedback they have received from clients. Be open to suggestions but have an understanding of what your remodel will entail.
[youtube]http://www.youtube.com/watch?v=eDJ6sN0cr9M&feature=player_embedded[/youtube]