Choosing Instance type for F5

as indicated in the documentation, it really depends, and sales would have the best answers for you. If I were to take a swag at your specified requirements, I'd say you'd be fine at the c3.large level for "good" feature set assuming most of your SSL is bulk encryption, but you'd want the c3.xlarge for "better" and the c3.2xlarge for "best" feature set. I reached out to sales to inquire on your licensing questions, I'll let you know what I find out.