"I tested them both and believe it or not I actually can select the left or right channel. "
That's great. Where or how are you changing it? In the Main Setup Menu in Audio options? All I see on the AUDIO button options is the full audio track, codec, etc.
I was going to look at MKVTools to see if you could eliminate a left or right channel and make a "new" mkv with just one channel's audio track. Would have to get the mpg into mkv tools but I'm sure that's not a problem.
Also Studio, although I can't stand what's happened to Pinnacle Studio, will import mpg's and you can do whatever you want with the audio and remake the mpg. I bet almost any video editing software can do the same with mpg's. Then you can make two files each based on and named based on the included language dialect.
I bet Sony Vegas, almost any of them will take mpg's and have full blown audio editing options.
Edit: Easy to do in Studio 12.1. Loaded the mpg, went to the Audio editing screen, can drag the audio to left or right channels, remake mpg and you have just one language track. Geeky looking dude with glasses.... If they made a movie like that in America the movie maker would be accused of racist Asian stereotyping....
Studio, and again NOT recommending what used to be Pinnacle Studio, can even take the one audio track file, reload it and "create" a surround sound effect. Not sure how pleasing it is nor what sound effects would be, guessing Jurassic Park would be anti-climatic, BUT you could do so.