If I just order the tower now without the Bimini and decide at a later date to add a Bimini, can I order the Bimini later and install myself?

Hello, Yes, you can purchase a bimini at any time. Just be sure to choose your specific tower on the bimini page to ensure it fits correctly. As for installation, that is completely up to you. If you feel comfortable doing it, there are installation manuals on the Bimini page under the resources tab.