If you start the bocourti small enough, 125 will work for a while.
They get about the same size as pearsei in the end, but may take a little longer to reach full size.
I got my bocourti, a little over a year ago at 2"+.
The first time I had them, maybe 10 or more years ago they easily hit 14+" in 3 years, and outgrew my 150.
I expect to put them in a 500gal indoorpond of sort in about another year.
I have them in a 6ft tank (think it's a 125) at the moment, and they are now 5" to about 7", they should probably be 10"-12" in another year.
They share the tank with some Chuco intermedia, and because they are essentially non-predatory vegetarians, they are able cohabit with many other fish, and being nonthreatening, I might cautiously try adult nanos (although I never have).
The bocourti have shared the tank over the last year with everything from Madgascans like Paratiapia and Paretroplus, to festae, to bartoni
Another thought, I don't usually keep fish of the same color and shape together, because I find they seem to sense competition.
But a nano, although "yellowish", is so different in size, the color thing may be mute.
And I find, large vegetarian cichlids find security in a presence of groups of smaller cichlids, just as they would in the company of tetras or other dithers.
