The one that Milokai and R1_Ridah have are Rio Tapajos, The ones at Rapps are Rio Xingu.
The one that I have is Rio Trombeta. (which is my favorite see my Avatar) although the Tapajos are very gorgeous also.
I have been looking for months... for some Trombeta Marms, But it seems that Brazil has really locked down its borders on exportation of its fish. So the only thing that I have seen in a Loooonnngggg time is the ones that Rapps has. So if you get some from Rapps be sure you post pics. I have been waiting for someone to get some and I can see how they look
As for as Lents, there are quite a few on here who will tell that they are better looking.
Which if you get the good ones they are gorgeous, but the ones that were around this summer and fall were a strigata/lent (see the thread called I think The Great Debate)
They are both gorgeous though but I would take Rosemarie over either, but as these aren't around here in the states and would cost 500-600 bucks apiece if they were, I'll stick with the Marms or Lents.
First pic is Trombeta ( hasn't gotten nice red abdomen yet)
Second pic is Tapajos (not all are this good looking)
Xingu from Rapps.