I think I would use X-10 motion sensors
coupled with lights and cameras. Using
FloodCams might be a good option, although
you don't want to use too many. You could
set it up so that a FloodCam could turn on
other regular flood lights, or just use in
conjunction with other motion sensing
lights. With X-10, thay have a chime that
could be set to go off when motion detected,
and you could view what's going on from a TV
in your bedroom, or where-ever. Also, you
could set it up with a VCR Commander to
record the action when activated, although,
going by the distance you listed, you'd have
to get some siganl repeaters and other
things to make it work from your home.
There's a variety of ways to do it, though.