I don't think you are going to be able to pass your required current through such a high RDson, even with maximum heatsinking or water cooling.
But! Maybe do a search at International Rectifier Home Page - Flash Detection and you will find FETs with much lower RDson, and then when you find one you like, see if Digikey carries it. Don't believe current ratings. Go soley on the RDson and sit down and calculate the power dissipation using thermal resistance yourself to find the REAL current it can carry.
To narrow down your search, choose the D2-Pak, D2-Pak 7-Lead, and Super 220, Super 247, TO-262, and TO-220 packages for your search. Only FETs in those packages will suit your current needs. Again, do not use the company's current rating as search criteria.