The cmdline.txt options in the linked topic will only rotate the console terminal, not the entire display. To rotate also EmulationStation's screen or the emulator video output, you need additional configurations - some details are in this topic.
The TV supports 1080, but I found the solution by hot swapping the unit after booting with the computer monitor. This boot up set the output to the monitors resolution. Once attached to the Television I had a clear and steady picture. Using the video set-up in the Retropie menu I set it up to use the monitors default resolution. I then shut down and rebooted, and the system loaded to the retropie config I had just corrected. Going back into the Retropie menu's video set-up, I was now given the option to change the resolution to television, progressive, at 720, which is where I wanted this to run to allow for portability. I saved and rebooted and the system loaded on the next try. Four reboots later the system is still easily displayed.
OK I don't know if this is the best way of doing this but it seems to be working. The new config files were saving to configs/all/retroarch/config. The retroarch file being looked at is in gba/retroarch.cfg. I simply copied the content of the new config file and overwrote the content in retroarch.cfg with the new data. I kept back ups of the original files in case anything goes haywire. So far it seems to be just fine. Thanks.