I think at this point it is worth to share my entire experience with my keyboard:
1) Keyboard design: after I realized I needed something really custom and I started to designed my keyboard with
http://www.keyboard-layout-editor.com. I think everyone on geekhack used this wonderful and very user-friendly site to design a keyboard. I read tons of threads on how to design a keyboard and very interesting stories.
2.A)Plates: the plate is quite complicated and stressful because basically you have one shot (100$ shot). Because of my constant moving between two continents, I needed to find something reliable for shipping and I found out that vectorealism is a very good italian small business. (
https://www.vectorealism.com). For the plate, I chose a stainless steel (not very ideal because of the weight), but the results were really amazing.
During this phase, I had two issues: the mount holes diameter (I choose 5 mm, but it is to big) and how to optimize the half squared meters of stainless steel to get more plate as possible.
At the end of the story, I decided to order just plates and one bottom (plate and bottom for my GELO, plate for one PLANK and a plate for numeric keypad)
2.B) Hardware: I choose the fairly standard hardware items: I bought a solder (GOCHANGE 220V Soldering Iron Electrique Réglable), a multimeter (Etekcity Multimètre Numérique Portable Professionnel), a teensy 2.0, 150 diodes (1N4148) , 100 ft of wire and for switches, Gateron Brown.
3) Build my GELO: It was my first time that I soldered anything and I started with my GELO. I took me a while to understand the technique, but now I am comfortable soldering. Matt3o's notes are fantastic (
https://deskthority.net/workshop-f7/brownfox-step-by-step-t6050.html) and so everything went smooth
until I started to solder the micro-controllers. My initial mistake was to solder all the wires to the keyboards and then try to connect them to the teensy. Very rookie mistake. Here the horror I made
4)Firmwire: Oh boy. That was tough. I download the qmk and started to code from the scratch following the hand-wire instruction. I was never able to produce a working hex file. I got tons of error messages and after two weeks I gave up.. I was desperate because I couldn't figure my bugs out: I decided that it was not worth to reinvent the wheel and I took the config files (config.h, gelo.h, gelo.c, keymap.c) from an existing project (I believe it was minorca) and modified consequently. In less than 60 minutes, my GELO was finally working.
END OF THE STORY:
My GELO was working, but it was far from being finished: the keymap wasn't completed and fully functional, the teensy connection was a mess such that I couldn't really close the keyboard with my bottom plate and the wires started to unsoldered by them self. I lived in Paris in a very small apartment and I didn't have really the space to solve all these problems, mainly because I moved to Argentina, so I packed all my stuff in boxes and I opened it only four months later.
Last week, I decided that it was a good time to continue my project and I desoldered the teensy and made some clean (??) work on my keyboard
As I was saying I still have some problem of registering twice some caps and the bottom plate is not yet ready to be used, but the keymap is done. (and I bought the amazing Star Wars XDA from keyclack).