Any version - 4.1.x / 4.2.x / 4.3.x / 4.4.x should be fine for WAE 512. Please make sure to select right image for central manager / application accelerator.
PS: Please mark this as Answered, if this answers your question.
Getting Started
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: