The main picture is a Diatone FPV250, the original “X” frame, without any chassis. Navio is a tight squeeze on those frames, but they are still my personal favourite (FPV250LH).
I think @Kevin_Goff is right and a bigger (but not as big as your previous monster) frame would suit you better. Also as you probably know already as you scale-up the motors/prop sizes the relative weight of the battery/electronics goes down so you get longer flight times. Just not so big that it’s like flying a baloon, you need some excitement 
There is one very popular build on this forum which I like as an example of a DIY, just self-cut pieces of carbon fibre plate and some tubes: http://community.emlid.com/t/my-next-build
If you want to a mass manufactured kit then the Diatone stuff is so cheap you can buy a few extra as spares. They also sell the small screws, correct length stand-offs and gimbal balls (with lock/safety bolts) if you buy direct (from China) via banggood.com.
Personally as I have a 3D printer, my next build will be hybrid between 3D printing joints and mounts along with larger carbon or glass-fibre cut sheets. There are many 3D printed quadcopters on www.thingiverse.com for inspiration.