If it's a hairline crack, it's likely it was caused by the foundation slab settling and flex.
It's totally acceptable for the concrete foundation slab to form hairline crack, that's just the natural of the concrete and it always happen during curing and settling. However during this settling and flexing, it might crack the tile on top of it if the tile was installed on the slab too soon.
Most of new build won't have tile installed until 5 to 6 month after the foundation slab was poured, but in the model home's case, the entire model home was completed in 3 month, it did not have enough time for the foundation to settle and probably more foundation flex/settling happen after the tile was installed and crack the tile.
Those wood looking tile looks great, probably more durable than wood. Just make sure get a good quality tile, smallest grout line possible (1/8 is standard but 1/16 will look much better) and dark colored gout (this will hide the stain so much better).
Regarding to tile vendors, here are a few good tile places. These places only sell tiles, you'll need to find a installer though.
Arizona Tile. http://www.arizonatile.com/ Nice showroom, good price, very friendly staff, give out free samples but the selections are not very large.
Dale Tile. http://www.daltile.com/ Good showroom, give out free samples, showroom doesn't have all the selection shown in the internet site, does not sell to customer directly.
Bedrosians Tiles. http://www.bedrosians.com/ Very nice showrooms, good prices, good services, but does not give out free samples.
Note: Arizona Tile, Dale Tile, and Bedrosians are used by the IP in all their homes for both standard and optional tiles.
Walker Zanger. http://www.walkerzanger.com/ Awesome showroom, incredible selections, located on Edinger next to Columbus Square in Tustin. It's expensive but you might find the same tile online or somewhere else cheaper. Give free samples.
Ann Sacks. http://www.annsacks.com/ Great showroom, great selections, very expensive. The showroom is located in Laguena Niguel.
Porcelanosa. http://www.porcelanosa-usa.com/ This is my favorite tile shop. Great showroom, incredible tile selections, give free samples, but very very expensive. Porcelanosa is located right next door to Bedrosians in Anaheim.