Nismo/ tomei will flow around 400rwkw on pump depending on who's tuning the car
The walbro's 400s seem to be the sh!t now, I've been running 2 of them in a surge tank with e85 for about 3000km and no issues so far. They are quiet as hell too
As for putting one in the tank, I don't think they are an easy fit like the 044s.. If my memory is correct Piggaz tried putting one in but opted for a 044 as it was less hassle