Where did you read that? As I already said this is "L7 Requests per second" counter not SSL TPS. Your SSL TPS can't be over 25k.
If you want to be safe and reserve some room for growth, go for i5800. If tight on budget, i5600 or even i4800 might be enough. i4600 will not suffice because it can only handle 650K L7 requests per second. We do not know if all your TCP connections are encrypted for HTTPS or if some are plain HTTP. With such TCP connection counters we can only make rough guesses.
My answer is i5800 is the appliance to go for. If you are unsure with my recommendation, go to AWS community forums or ask their support. Try to figure out exact numbers you can refer to in F5 product datasheet. Once you have numbers, cherry-picking your appliance is straight forward. If you prefer not make decision yourself, just open a thread here or turn to your local F5 reseller.
3 Numbers should suffice.
During peak hours:
- SSL TPS. (Take note that hardware SSL TPS numbers are different for ephemeral keys and RSA. Perhaps something to keep in mind if your company policy is to only use ephemeral key suites)
- TCP Connections per second
- L7 Requests per second
Regards,