new to wheat ?s

Need to combine 100 ac of wheat ,and need to keep the straw. I run a '03 2366 with a specialty roter. Need to know what to run for seives, have 1 5/8 in top and bottom will they get a clean sample. Is it worth getting a shorter bottom seive. I do alot of oats as far as small grains go. Then i do corn and beans the rest of the fall. Some corn is high moisture for dairy cows. I run slotted grates and large wire concaves for oats. Then put keystock grates for corn and beans. Please post any suggestions

Thanks