Since you are upgrading from a size 48 panel, the 55 looks like a preferable option than a 2-inch upgrade of 50.
Between the two Samsung panels you shortlisted, my vote goes to JU6000. The J6200 is not bad at all, especially if you don't need 4k for your viewing needs.
Now, if the dealer throws in a pointer remote control with the JU6000 that's even better. I know that not all UHD panels come with this pointer remote control so better ask.