From what he is saying. He is planning on 3C. That option is Ethernet hard wiring from one router to the second. If your gigabit hard wiring your APs it is the best possible solution. I would not recommend using method 2 on this list either. Powerline is great for single hard wired connections (esp if your house is <15 yrs old). However, sending multiple connections through a wireless AP and then to a powerline you will likely see bottlenecks. Your adding delay at too many steps and the input lag climbs with each.
As with any network solution. It is only as good as the equipment you put into it. I only buy top of the line routers, cat 6 cables, and I always use my own modems vs the crap that the ISPs provide. If you buy 3 trendnet APs for 20 bucks a piece you will probably have a lot of rebooting in your future.
My specialty in IT is not networking. I have my own software development company, but I still have to deal with these kinds of things a lot. I have used just about every solution there is and to date hard wiring APs and cascading them is the best option I have found. There is a reason it is how just about all businesses set up their networks. If they can run 200 RF devices off 3 APs in a warehouse then you will be fine running your iPads off them in your house
If you absolutely cannot hard wire your APs then there are viable options, but they will all be a sacrifice in speed and reliability.