Hi Mr BoatingBango.
Based on your location and TVFool signal results I would recommend a UHF only antenna. The reason is you only have one VHF-hi station on channel 11, PBS station WTVI-DT. So unless you want to receive that station specifically you only need a UHF antenna. You will still receive PBS station WUNG-DT and possibly WNSC-DT
Ok so what type of antenna you ask. I would recommend a
AntennasDirect DB4 UHF antenna.
http://www.amazon.com/Antennas-Direct-DB4-Multi-Directional-Antenna/dp/B000EHYG9K/ref=sr_1_1?ie=UTF8&qid=1295654965&sr=8-1 
They cost $45 from Amazon, you will also need a J pole to mount it on they cost about $25, finally you will need RG6 coaxial cable with F connectors, Home Depot may sell precut and pre-fitted cable with F connectors. Not sure if your existing Charter cable feeds multiple TVs if it does run the RG6 from the antenna to the distribution splitter that feeds all your TVs otherwise directly to your TV.
Attic installation should work OK at your location, if you are missing a few stations then you may want to consider a roof mount using the J pole on the roof, side wall or gable. If you install on the roof you need to consider grounding the pole, the benefit of a roof mount is you could run the RG6 directly to the Charter cable grounding block on the outside of the house as the feed in point.
I would recommend pointing the antenna in the direction of 150 degrees magnetic or SouthEast, the reason is these are your weaker stations and about 22miles away, the local stations are only 15 miles in the SouthWest direction at 232 degrees magnetic and should be received off axis without any issues.

If you have any other questions feel free to ask.
Good luck and welcome to the cable cord cutters club.
Regards,
Cutthecable
http://www.tvictory.com