Yes, you will need a converter box. Amazon still has a few available. SolidSignal still has the CM7000 unit which many consider worth the extra $'s
http://www.solidsignal.com/pview.asp...r%20Boxes&sku=
A single antenna aimed at 155° per your compass should receive the majority of the major networks. Try to find a mounting location that can 'look' between the trees and buildings. Here are several similar antennas...
http://www.solidsignal.com/pview.asp...0Antennas&sku=
http://www.solidsignal.com/pview.asp...0Antennas&sku=
http://www.solidsignal.com/pview.asp...0Antennas&sku=
http://www.amazon.com/Antennas-Direc...9106645&sr=1-1
Because you are not going to split the signal to multiple sets, I would attempt to run without an amplifier, adding one if it proves necessary is not a big project.
Regular RG6 coax is the right cable for OTA applications. (Quad-shield is OK if you already own it, but save your money otherwise.)