Simple-There are tons of realtor websites that allow you to select an area and put in your pricing requirements. You can then look at pictures of the homes online. They pull off the local MLS which has all of the realtor listed homes. You can sometimes get hooked up with a realtor this way as well.
As for a broker, many companies go nationwide. Look at Countrywide or some other national mortgage company. You might not get the best rate this way, but at least you can get pre-qualified for the amount you want to spend.
For instance, try this site for home information.
St. Louis Real Estate (first link on google)