Cat 6 cables are designed to support Gigabit Ethernet standards (1000BASE-T/1000BASE-TX) up to a length of 100 meters. They offer improved performance over Cat 5e in terms of crosstalk and system noise reduction due to more stringent specifications for shielding and twisted pair designs. Cat 5e also supports Gigabit Ethernet but has higher chances of crosstalk compared to Cat 6, which makes Cat 6 the best choice for the given criteria. While optical fiber offers even higher speeds and reduced noise, it is not necessary for distances of 100 meters when Gigabit Ethernet is the required standard. Coaxial cable is generally used for cable Internet or digital TV instead of data networking for office use.