The SSPX, or Society of Saint Pius X, is a schismatic organization which is not "Catholic". They have separated themselves from communion with Rome, and so your attendance at one of their masses doesn't "count" for your Sunday obligation. (I.e., you would still have to go to mass at your own church to keep the Sabbath obligation.)
For a Catholic organization (and not some odd-ball schismatic group), try the Priestly Fraternity of St. Peter -
http://www.fssp.com/main/index.html.
For a regular Latin mass in your area, this site ought to tell you the closest "regular" one:
http://web2.airmail.net/carlsch/MaterDei/churches.htm
For more info on the SSPX and why they're not properly called "Catholic", see here:
http://www.catholic.com/thisrock/2003/0304fea2.asp
God Bless,
RyanL