Whole grain needs extra support so the correct pan size will make all the difference in the world in the height of your loaf. Metal pans work great but you could use anything. I have found a pullman loaf pans are very nice they have 4 inch sides and are 4 x 8 approximately. You can buy them with or with out the lids. The high sides allow the dough to climb up the sides, and make a perfect size for putting in the toaster.