Default Accessory compatability between S4 models

Apologies if this is obvious to everyone here, but I haven't been able to google my way to a definite answer.

I've been looking at batteries, cases and chargers, and I can find lots of things marked compatible with the S4...but not for the S4+. Are all accessories interchangeable between different S4 models?

So...is a battery marked as compatible with the Samsung S4 (GT-i9500) also compatible with the Samsung S4+ (GT-i9506)?
I noticed at least two different model numbers (B600BUB and B600BE), but is there any difference between them?

Related to the battery question, I want to get a battery charger like the EB-K600BEW (sorry, can't link yet), but can't find one for S4+.

Lastly, will an S4+ fit in cases made for an S4?