should I do any other form of amplification or do you feel this is solid enough to split the signal out 4 ways?
Not quite sure what you mean completely... The idea is to take the single video feed and be able to display it on up to 4 separate video devices.
So should I build 4 exact copies of the amp for each output with a single driving input?
That defeats my purpose, what are the commercial units doing that I can't do?
what would be the best circuitry to drive all 4 outputs properly?