You may find an amplifier unnecessary, even a source of trouble. You have plenty of signal power to work with. Antenna gain is always better than amplifier gain. (Amplifiers add noise and distortion, antennas don't.)
If your home construction does not include metal (such as stucco reinforced with wire, metal siding or foil faced insulation) a simple non-amplified indoor antenna (example:
Terk HDTVi not HDTVa, or the
RCA ANT-111) should be capable options.
A more reliable option would be an outdoor antenna. Some viewers in the Bay area have had trouble with multipath and have had to opt for a more directional antenna. The HBU-33 is a good choice, so is the Winegard HD7694P. Either antenna has more than enough gain to drive 100' of RG-6 and a 2, 3 or 4-way splitter with no amplifier.