These two orthographies should be the only ones now, but it's common on all three islands that people will mix them up and not write 100% phonetically or 100% etymologically. This happens usually when writing informally. This is more common in the older generations since papiamentu has only been part of the education system for only two decades. Although reading either of them should not be too difficult.
I don't know too much of how the papiamentu looked like in the past. But a couple of years ago our papiamentu teacher at my high school showed us the oldest letter/document written in papiamentu. In this case it was a love letter and it was difficult to understand what it said. It was certainly different from current papiamentu and really etymological with in my opinion more much germanic words than current papiamentu (could have also been than the guy that wrote it just used more germanic words). As the years passed papiamentu began borrowing more and more spanish words until in begin or mid 20th century there were people that began to feel that papiamentu was being replaced by spanish. Here is when efforts to standardize the language began. Which resulted in the two current main standards.
If you want to hear papiamentu. I recommend you to just browse the internet and look for videos. The youtube channel of tele Curacao is a good source of videos in papiamentu, most is local news but you might find something else there. Some local radio channels also stream online, which you can hear at http://www.basilachill.com