Wow! Lots of good info here for sure.
Sounds like your best option is to put the antenna in the attic.
When aiming one of those multi-element "fishbone" antennas, remember that the open end of the "V" is supposed to point towards the signal. However, since the strongest signal may not be the most direct one, most folks find that rotating the antenna till the signal is strongest works the best.
Signal amplifiers are communly misunderstood. Many folks think that they're a cure-all for all of their reception problems. In reality, they are only useful when you have very long cable runs or lots of splitters. Since you have neither, I wouldn't bother with them. They can cause more problem than they solve.
One trick to improve twin-lead's performance is to twist it a couple times per foot. The twisting helps reduce any interference it may pick up. For a short run of cable like yours, this may not make any difference. Co-ax is already inherently resistant to this type of interference.
If you go with coax cable, RG6 cable has less loss than the more common RG59 cable. Again, for short runs this won't make an appreciable difference.
Good Luck