you may want to check this out-- If you have been using your M970 in the top pull configuration, the same set up will not work on the Ultegra. The Ultegra requires a fairing on the bottom of the bottom bracket shell and the cable comes aroung it and up to the derailleur. If you have been using the M970 in the traditional configuration a road derailleur will work. The Tiagra 4500 or the 4400 is a reasonably priced dependable derailleur. Shimano 105 is also a nice FD, but I don't notice any difference in shifting--just a little more bling.

http://techdocs.shimano.com/media/te...9830686340.PDF