The SuperHornet is not a legacy platform, it's widely accepted to be a 4.5 generation aircraft and it's proven, it's available, oh and compared to the F35 it's cheap
Superhornet is a re-worked design of a legacy aircraft with a newer radar - call it 4.5 Gen if it makes you and Boeing feel better about where it really lies in the future - next we'll be seeing 4.75 gen, 4.99.... For the long game it is a bridge capability if you wish to upgrade your older F-18 while awaiting F-35 or simply cannot afford to buy an entire fleet of 5th Gen.
I believe that when F-35 production ramps up we'll be surprised at how reasonable the flyaway cost is for what you get. You want legacy then fine, it will cost less because Boeing are being pushed out of the fighter market by Lockheed for what will be the THE future long-term western strike platform. Hell I bet they even subsidise the cost from their airliner sales just to make it attractive.
AOA won't win a war of the future so why buy into it now?