In search of true 3BR

if your willing to take a walk up, you could probably find a true 2 bedroom.

I meant true 3 bedroom

That's a toughie as far as the UWS goes. Same with close-in Brooklyn, too. But you knew that already. A SE search turns up only 26 UWS listings, and half are dupes of one apartment. You should be able to eliminate those in a day, and then turn to figuring out how to make a two-bedroom work.

in your price range, your best bet is to find a 2 bedroom with a dining alcove that you can use as a bedroom. Lincoln Towers has such apartments that can easily be converted into a 3rd bedroom.

That kind of postwar apt with the L-shaped living-dining is much more prevalent on the UES. Doesn't matter, as most (like LT) are co-op and backtonyc probably won't want to move in two years.

I think your first idea, a cozy railroad flat with cubbyhole bedrooms for the kids, is more like it for the money.

Look for a large ground flr/walkup north of 96th.