McKay Dymec made an AM only tuner and AM only antenna; the best I have ever heard and certainly in the hunt for AM state of the art. Good luck.
If you are looking for a decent AM antenna - you might want
to check out the AM only model from Terk. It is also sold
as the AM Advantage Antenna - the same antenna, but with a
different name (and much lower price point).
As for getting decent AM reception - you might want to
look into one of the older McIntosh Tuners - MR-74 & MR-75
are good choices - because they are AM & FM models. They
not only have very decent FM reception, but good AM, as well. I personally listen to some talk radio programs on
the AM band of my McIntosh tuner, and really enjoy the full,
mellow sound I receive.
One last thing - if you buy a McIntosh Tuner and for
some reason you don't like it - you can always turn around
and sell it for pretty much what you paid for it.