Depends on which one you want.
For a V2: Anakin Starkiller here still has some available over in Project Runs, last I heard, which was just the other day. There's also the RPK Customs one, which is still available, and the new Solo's Hold, which is coming soon. The AS can also be used for a V3, if that's the one you want.
For a V3: The AS can be used for this, and Roman still has some in stock, although that one is definitely the way it looks today, as opposed to how it did in RotJ.
For the Hero: This is where it gets tricky. I don't think there actually is an accurate RotJ Hero readily available at the moment. If you're okay with getting one similar, there's the Creepy Uncle that just came out, which I believe is sold out but I'm seeing them up for sale often enough that I think it'd still be relatively easy to nab one. Roman also has the Balance, and that one's in stock. Both of those are based on TLJ, so they aren't screen accurate to RotJ. If you're dead-set on RotJ screen accuracy, there are two that I'm aware of: Evolution Arms and KR Sabers, neither of which is in stock and KR Sabers doesn't even have it on their website. Evolution Arms doesn't sell empties, I don't think, so it would be a fully-installed saber, and it's the one Vader's Vault uses. EDIT: Should have finished my scan of the forum before posting, AS has been talking about doing a run of screen-accurate RotJ Heroes, uneven rings and all. It's hardly imminent but it's something to look out for.
I do want to note here that when I talk about "screen accurate" I'm referring only to what they're attempting to do. Both pairs of TLJ and RotJ Heroes I mentioned look different from each other, so they can't BOTH be right, and the RotJ Heroes are idealized versions, lacking the uneven rings the screen-used one had, since it was based on yet ANOTHER variant, the Yuma, which I don't think anyone has done a run of.