achilles splint

I had alot of foot pain the last few times I ran.
So badly in my achilles tendon and on the top of my foot, and my calf, that I had to stop running.
I went to the podiotrist who said I am “over-pronating”.
He suggested a rigid arch support which I have, and a splint to wear at night to stretch the achilles tendon to make motion in my foot easier so I won’t over-pronate.
Which brace is the best one for this, to wear while I sleep?