The converter input current will be > 200 A, the peak current respectively higher, depending on the inductor size. Four 2SK2266 can theoretically work, but conduction losses are a bit high, one would probably prefer lower total rdson, either more transistors or a different type.
MOSFETs have a positive thermal coefficients, so a parallel circuit will be self-balancing and doesn't involve problems.
Presumed that you are interested to reduce input ripple current, the converter would preferably use a dual phase topology.