First, welcome to Tropical Fish Keeping forum. Glad to have you with us.
As for the reliability of that site, I have never ordered from them so I can't say on that score. But they do seem to have the name of this pleco mixed up. According to PlanetCatfish, the Rio Nego Pleco is Peckoltia
sp. L135, possibly Peckoltia braueri
. You can read more here: Peckoltia braueri • Loricariidae • Cat-eLog • PlanetCatfish • PlanetCatfish.com
I ttrust the info on PlanetCatfish. The species epithet platyrhyncha
belongs to a very different loricariid.
That out of the way, like all pleco the male is territorial to specifics (other pleco, sometimes other substrate fish) but is usually peaceful with upper water fish. Give him lots of bogwood, including some pieces positioned so that there are hiding spots under or within.
There are lots of suitable characins and cyprinids to include with those mentioned; have a look at our fish profiles, second tab from the left in the blue bar across the top of the page.