Here's a picture of a motor controller I have been using for several years. It runs on 12V at well over 100A when under load. I used 4oz copper and kept everything short. The FET drains are soldered flat on the board, and the board is on a heatsink. I have had no problems with that arrangement for intermittant duty. As pointed out above, the full capability of the MOSFET may be limited by the lead size of inexpensicve packages, such as TO-220 or DPak, and one would have to go to a more expensive package to get screw terminals.
Let me add that for even greater power in an earlier design, I cut traces from 0.025 inch copper plate, which was obtained from the local hobby shop. The traces essentially duplicated the PC traces in outline and were attached to a heatsink with a thermally conductive adhesive and insulated screws. Heavier copper than that is much more difficult to work and to solder. I have not compared the two designs for maximum current capacity. I have added a picture of the board made in that way. The thicker copper conductor is shown in the closs-up.