What windowed Sinc might be closest to a Parks–McClellan low-pass filter?
none.

what you're asking for is what window, which multiplies a sinc() function, will get you an optimal impulse response kernel, like you might get from Parks-McClellan.  well, to get that window, you must undo the multiplication.

the problem is that you cannot divide by zero.  any of these "sinc-like" functions that come out of P-McC will pass through 0.  but not necessarily at the same place that the sinc() function goes through zero.