Converting my old mountain bike to a cyclocross I have a 1992 Bridgestone MB-4 that I am converting to a cyclocross bike.  It is a 3 x 7 (21 gears).  I am going to put down bars on it and to change the older over shifters and brake levers.  As it is an old bike, I am looking to keep the cost down on parts.  Does anyone have a recommendation of combined brake/shift levers that will work with 3 x 7?  I have Deore XT rear and front derailleur. Any other suggestions/recommendations for this conversion are also welcome.
Integrated drop bar shift levers are inherently expensive, so I'm not sure how much you will be able to keep the cost down.  Also, you will probably have a hard time finding 7 speed integrated levers. They would either have to be old, or low end.  And even the low end stuff is quite highly priced.  Based on the searching I've done around the web, it doesn't appear Shimano ever did 7 speed intergrated shifters above the Sora Level.  When Dura-Ace and Ultegra were in 7 speed, they were still using down tube shifters.