At the risk of seeming a shill for Magnum Dynalab, you should get their MD
205 "signal sleuth".

http://www.magnumdynalab.com/md205.htm

It doesn't just boost the signal. It cleans it up. Remember to put ferrite
chokes on the AC power cords of all your FM equipment (and possibly the
audio cables), so the good work done by the MD 205 won't be undone by direct
RF entry.