Even if the OP were to go the trigger shifter route, OP could do it for much less than a "new" bike plus drop bars. Plus, as AlTheKiller notes, this is not an upgrade per se. It would move shifting higher than the downtube, but I would not consider it, since it still forces one to move a hand into a less stable position. STI's or bar-end shifters would be an upgrade (at least in my experience).