Welcome, Holly.
I think the smallest joist in that series is 9 1/2 inches tall, so you're in fine shape for joist structure.
Just keep in mind that you're right at or near the minimum subflooring prescribed for the various CBUs and isolation membranes. More subflooring is always better.
There is no advantage, by the way, to using the thicker CBU. If your subfloor qualifies, you can use the 1/4 inch CBUs as well.
My opinion; worth price charged.