Since the front shifter is indexed, it probably won't work well with the mtb front derailleur, the cable pull ratio is different between Shimano road and mtb front derailleurs. The rear shifter will work fine with the LX rear derailleur, as long as the shifters have the same number of "speeds" as the cassette.
As for a "road" front derailleur working with the 46/36/26 chainrings, I'm currently using a 105 front derailleur on a 46/36/24 setup. It works beautifully. I did use a dremel tool to reshape the 105 FD cage a bit. But I'm using bar end shifters, with friction shifting up front, so I don't know how well it would do with indexed shifters.
There's a front derailleur, the IRD Alpina, that would be well suited for that, however. They're available from Harris Cyclery-
Last edited by well biked; 01-17-08 at 04:11 PM.