You'll also have to cut the finished counter to the dimensions of your kitchen, creating an unfinished edge that must be covered with a matching strip of laminate if exposed. Another option is to buy the countertop through the kitchen department of a home center or from a kitchen dealer or designer. Your order will then be sent to a fabricator. Or you can seek out at a cabinet shop that makes its own tops. In all cases, you're best off having the pro come to your house to measure.
Most fabricators deliver the finished countertops and offer installation.
Whether you choose this option or not, you should carefully inspect the finished countertop before installation. Because of its limited expansion and contraction, MDF won't crack or buckle the laminate. Also check for a small section of MDF spanning the seams beneath the counter where two pieces of fiberboard come together. This piece adds strength. Check that the laminate is fully bonded to the substrate.