It is all dependent on where you live. Some states/districts only allow you to list one SA and speard the wealth on Noms. Take a look at the nomination forum and sticky for info. Plenty of districts allow multiple noms. It all depends on your MOCs. Your BGO and FFR probably know your area best and can tell you what the MOCs do. You can also ask the MOC POC they provide. This issue comes up every year, read some of the old threads to see the different perspectives.
Yep! My daughter was nominated and appointed to USNA, USMA, USAFA chose USNA. Apply to what you choose, put together the best application, sit and wait and let the chips fall where they may. Good Luck!