The sw-29480 is also sold under several other names/brands. I have not developed any respect for it's build quality and I have absolutely no trust in the claims regarding it's performance. I don't recommend the antenna to anyone.
Here's a generic TV fool report for your ZIP code:
http://www.tvfool.com/?option=com_wr...1dda4096d28d03. Given the flat terrain in your area, it's reasonable to suggest an antenna based on this TVFR.
You should be able to get reliable reception with a simple, non-amplified antenna such as the RCA ANT-751 or the similar Antennacraft HBU-11. Pointed at about 40° per a compass you should be able to receive signal from north and northwest at the same time.
You should be able to split the signal to several TVs without needing an amplifier, just a passive splitter with the same number of output ports as connected TVs.