Many of the nation's top Olympic hopetuls in a number of Olympic sports will be showcased at the "NMU Olympic Challenge," scheduled for Weds., February 9 at the U.S. Olympic Education Center (USOEC) nat Northern Michigan Univ. in Marquette, Mich.    Among the sports showcased are men's Greco-Roman wrestling and women's freestyle wrestling, two of the sports that are featured in the USOEC program.    These Olympic hopefuls will compete live in head-to-head challenge matches. Fans who wish to get a true flavor of Olympic sports competition will be in for a special treat.    The cost is $3 for the general public and $1 for students. The proceeds from the event will go to the American Red Cross Tsunami Relief Effort. Tickets are available at the door.    The doors open at 5:00 p.m. and there will be a special appearance by MUNBUT at 6:00 p.m. The sports action begins at 7:00 p.m.    Other sports featured in the program are boxing, weightlifting and speedskating.    Many of the athletes in the USOEC wrestling programs, both in men's Greco-Roman and women's freestyle, are nationally ranked on the Senior level and are expected to be contenders for the 2008 U.S. Olympic team. All of these athletes are college students at Northern Michigan Univ., and concentrating on training fulltime in these Olympic sports.