After a few days with Navigation Bar-Softkeys, I grew tired of the persistent icon and an extra tap to get the softkeys to come up. RAM and battery drain was no problem for that software package.
I've moved on to
All in One Gestures last night and I already think this will be a much better solution. I couldn't install it at first, I had to download the Google text-to-speech module from the Play store so my accessibility settings could allow AIOGestures to work properly.
After configuring the offscreen swipes for Home (swipe bottom), Back (swipe from left or right), and multitask (swipe from either bottom corner), the device is much more usable with one hand and even better not needing to use the physical buttons. AIOGestures also offers a bunch of other options for configuring other buttons (long presses, and double taps). It will even learn the active button and you could configure it from within this app.
So far, this has been the best solution for me. However, some of the Google Play Store reviews mention a big battery drain, so I'm going to monitor it. However, since this brings such good functionality to the phone, I would have to see significant drain not to use it.