I am looking for an FM antenna amplifier

I second the "check out ccrane.com" advise already given. Having owned and tried a couple of amplified antennas, I tried the ccrane non-amplified FM Reflect and was very satisfied, especially after bending it into the circular patern. It's only $25 and a 30 day money back guarantee.

Bob also describes what I have done, (with a different antenna), including the RG-6 cable.

A broadband Wineguard or Radio Shaft RF line preamplifier (with the FM trap switched OUT) mounted at the antenna head is one good solution.
The Magnum Dynalab Signal Sleuth, which I also use, is really nice because of its' tunable front end & variable gain. It is also switchable on & offline from the front panel.
However in either case you'll still need a good quality antenna as your signal source for quality results. Also be sure to use good low loss feedline, typically RG-6 coax.

Do you own a home? I put a big roof Winegard TV/FM antenna in my attic, and then tapped into the cable TV outlet that runs to the room with the stereo. The tuner just plugs into the wall.

I use a Winegard preamp to boost the signal.

There is an excellent one, made by Magnum Dynalab, called the Signal Sleuth. As it happens , there is one offered here at A. Look under http://cgi.audiogon.com/cgi-bin/cl.pl?misctunr&1028827506&class&3&4&.
No, I don't know the seller, but I use one with excellent effect. Cheers,
Detlof

The Reflect antenna from ccrane.com is not an amplifier, but just a very good dipole, the best I've used.