check with your CAA TA. I believe they only sell certain day number tickets.
However, I believe you can upgrade any ticket at the gate (presuming CAA tickets are like others), by paying the difference at the gate (I don't know if you can get the CAA discount then).
Disney charges the most for one-day tickets - than the cost per day goes down incredibly. A 10-day ticket is incredible value. You can upgrade a 5-day to a 10-day for a set amount, and your TA should be able to give you a spreadsheet of the differences - or at least tell you the dollar differences.
The non-expiry option is expensive - but it's a great feature. Again, your TA should be able to tell you how much you pay for that option, and price out the differences for you.