Shimano compatability charts state that you can use a CN-7900 (Dura-ace), CN-6600 (Ultegra), or CN-5600(105) on that setup. Relative to the 105, an Ultegra chain has galvanized exterior links, and a Dura-ace has plated inner and outer links as well as perforated inner links for a modest weight saving of about 20g. Pins are chromed on all chains so expected wear shoould be identical.