i'd just like to throw in my two cents here. A lot of people, on this forum tend to ignore my posts, but I thought maybe I could be helpful here.
In regard to Gearbest.com.....there are a lot of things that can be purchased from them. I've ordered from them several times before, including two recent purchases. The only negative thing that I can say about them, despite the US warehouse that they do have, it still takes 2+ weeks to get my stuff.....but the stuff has always worked and has arrived undamaged.
You said that you were looking for a quad frame that was inexpensive and you also wanted to be able to replace the arms, if/when they get damaged and you wanted to have the components inside the frame. Here are my thoughts on that....I'd suggest the ZMR250 quad from BuddyRC.com. They are in Ohio and their service and shipping are awesome. I love ordering parts from them. The ZMR250 is a great frame for beginner and advanced flyers. I've had my ZMR for over a year and it's still solid. Here is a link to BuddyRC's page for the ZMR250, including spare parts:
ZMR - Frame Kits - Multirotor - Quad & FPV
However, for the price of the ZMR250, if you are thinking you'll need spare parts, just order two kits. That's what I did. I can tell you that this frame can take a beating. Although I do run 5" props on my ZMR250, it does have the room to run 6" props, which I also believe was a stipulation that you mentioned.
As for other components, I run Sunnysky 2207-2100kv motors (also available from BuddyRC). They are fun on 3S with 6" props and it's one hell of a ride on 4S with 5" props. You can also get some 20amp Spedix esc's from BuddyRC and they should handle the load quite well. I have 20amp LittleBee BLheli esc's on my quad and they always come down just slightly warm. Awesome esc's.
If I remember right, you were talking about getting a Naze32 flight controller. I have two Naze32 flight controllers and they work quite well. But, here in the near future, Cleanflight and Betaflight are going to stop support for the Naze32 flight controller because they are "older technology." What I mean by that is that the Naze32 is an F1 flight controller. Most flight controllers, these days, are F4 or higher and the developers are focusing more on those boards because they are have faster processors and more storage space for functions and updates. My opinion, avoid the Naze32 boards. I might be upgrading my flight controllers, in the near future. If I do, I'll just give you one, if you still need a flight controller. I've recently been shown the Omnibus F4 V2 flight controller. It's a $24 flight controller, from Banggood and Gearbest. It has an integrated OSD and onboard BEC. It also has a micro SD card slot for Blackbox features. There is also a really nice and easy port that a M8N Ublox GPS unit ($20) can simply be plugged in and that will give you RTH.
I'll scroll through the rest of your thread and see if I can be further helpful. Have a good day!