Actually, one could be more or less the same as the other. Let me explain myself:
1. The LM1881 is 10x more expensive ($1.5 compared to $0.15) -kidding
2. The 74HC14 maybe a "cleaner" solution, but I am worried that there could be timing issues -the sync signal could be faster or slower than the video signal, due to the buffer. Also, is somewhat more difficult to solder on so small pins...
3. What about focus video encoders? (only saw conexant there)
All in all, this pdf is an inspired resource, worthy of mention. I would recommend trying out the buffer solution if you're up for it -you certainly have nothing to lose.