What Nav firmware do I need?

Hi,

I am new and have a peugeot 5008 that was built in 2010 the one the flips up on loading. There are different types of firmware in the sticky do I need rt4/5 or do I need the wip nav plus?

When I got the version currently on it said rneg_d_R50b_R50.03 so want to put best version on so car is up to date then obtain new maps after that.

What should I be downloading? Any help greatly received.

Thanks,

Paul