JJOS 4.97

I'm looking to upgrade my JJOS from version 4.97. Any advise or suggestions?

The final decision was, I bought a 16g flash card and it doesn't work with the current version. I heard it will work with other JJOS'.

You can freely install JJOSXL to try it out, it just wont allow you to save. But if you are happy with JJOS1, first update it to v5.00 (the latest) and if your card still doesn't work, get a different card that's verified to work. The MPC1000 forum has plenty of recommendations.