mh74,
GREAT !, as you can see, even the 20' pulled LOTS of channels into the LOS (Line of Sight) for you. However, I'm thinking that with a three story house, with even a 10' Mast, mounted on your roof, is going to put you at about 30'.
I'll definitely go along with Dave, on suggesting that you not try for your Channel 2 or 4, and settle for a "Modified" (Channel 7-69) Antenna.
I think you'd be better off with the Winegard HD7696P, given it's healthy gain.
I'm not sure just how Amps got brought into this, but, you're really a little too close to your stations, to consider one of those. IF at some point you think you'd like to try one, there are some mild units, rated down toward 25 miles you could try, BUT, only as a last resort.
Remember, to use good quality Cable, Splitters, and ground your system !
Have a good Day !
S.W.