Weakness in the overall financial sector sent the Dow Jones industrial average down about 180 points.Wall Street retreated yesterday after Fannie Mae and Freddie Mac fell to their lowest levels in nearly 20 years on concerns the government might need to bail out the mortgage financiers. Some people may think that once they have found the house of their choice, their shopping days are over. Actually, choosing the house is only the first phase of the whole process. The next step is to find a mortgage with payment terms that fit your budget. Thus, where you shop and what to look for are very important in this stage of home buying.