The HD7694P has plenty of gain in your application. If you get it above the roof that's blocking the view toward 330° I expect the results will improve quite a bit. Can you consider a tripod or gable/eave mount?
Don't be too hasty about adding a preamp... the antenna needs to receive a usable signal before the amplifier will have anything worth amplifying. If you are driving many TVs, a distribution amplifier with high signal level capacity or a preamp with the same capability may be needed.
Given the fact that your signals of interest are scattered around the compass, you may want to consider a few options.
http://forum.tvfool.com/showthread.php?t=2882 and
http://forum.tvfool.com/showthread.php?t=820. If only one set is connected, a rotator may work for you. A/B switches are easy to understand and operate. An auxiliary tuner is one of the most channel surfing friendly options in my opinion. Network attached tuners are not for folks who are technology adverse.
If I were in this situation, I would be using at least two antennas:
A simple option would be the HD7694P aimed south. and an Antennacraft Y10713 pointed at 330°. I would look at the current cost of an AC-7 tuned for real CH-13 (tinlee.com) vs. an HD tuner.
There are quite a few other ways to go about this, particularly if you wanted to go after the weaker distant signals.