Santelli is one of the longest established vendors in the U.S. They make good mid-range uniforms, but some of their entry-level items aren't as competitive anymore. Their masks are a bit dated in design (not much interior padding), and you need to be aware that their lowest priced masks have snap-out bibs that are not permitted in competition (they do not make this explicitly clear in their catalog).
Blue Gauntlet is one of more popular vendors for entry-level equipment. The Fencing Post offers a 20% discount for e-mail orders. You can find links to all of the US based vendors at the
US Fencing Association website.
How long a foil lasts depends on the quality of the blade and how it is used. A foil that is used primarily in classes and lessons by somebody keeping good distance and not making excessively hard hits wil last much longer than one used by somebody fencing intense bouts who tends to hit really hard from close distance. FIE Homolgated (Maraging) blades can be expected to last much, much longer than inexpensive carbon steel blades. For carbon steel blades, some people will only get a few months out of a blade, others can get a couple years of frequent use. Foil blades are replaceable-- just buy a new blade and mount your old hilt parts on it.
-Dave