Time to start a new build (with your help)

Since I have made up my mind to get a pre-ordered Yuneec Typhoon H for my Video drone and
a couple of starter (learning) drones:

Potensic® Upgraded X5C-1 Syma Explorer 2.4GHz 6 Axis Gyro 4CH RC Quadcopter with 2 Megapixels Camera

and

JJRC H20C Nano 2MP Camera Hexacopter Quadcopter 2.4G 6CH 6Axis Headless Mode RTF

I also bought a Fly Sky T6 because of the good reviews but I also want a i10 to go with my new build.

I have plenty of battery chargers (been working with LiPo's and LiOn for years)
I have been in Electronics most of my adult life and am good with mechanics and a fair programmer, although I really don't want to go that far because my brain is getting old.

I think it's time to get started building my own from scratch.
I have no clue where to start.

I was looking at getting a frame first. I guess maybe a 300-400 size but I am not even sure that's where I need to start. I want to build up to getting all of the better parts to assemble this thing. I would imagine by the time it will take to assemble it all I will know a lot more about this hobby.
Buying a kit is not out of the question as long as I can customize it as I see fit (interchangeability is the word of the day)

I am close to retirement so I will have plenty of time but I want to get started because you just never know what tomorrow will bring.

Any thoughts?

Thanks ahead of time, Dave