I see no reason to have two scores from different years. I would take a timed practice SAT and see how you do and if you like the test format better, then switch. Most testers are better at one over the other.
If you stick with the ACT, make sure to prep well for it before you take it again. I suggest a test date over the summer as you will probably have AP exams in the spring and will want to have good grades ending your junior year.
A 32 is a very good score but you can probably increase that score a point or two with more, focused practice.