First of all, I'd like to thank John and everyone participating on this forum, sharing the knowladge! It's only because of this forum I finnished my project! You guys are the best!!!!
And another thing... I made the panels in 4 days from the moment the actual construction started... With everything bought and prepared, you could easily complete the first step in one day!
Anyway... to the fun stuff...
1.)
I bought 2m3 of DP-8 (80kg/m3) and 2m3 of DP-5 (50kg/m3), eqivalent to 705 and 703, I was told . And many 400cm long 14,5cm wide and 2cm thick boards, some glue, screws, burlap, etc...
The dimensions I chose are: 1m x 1,8m. That makes for 3 panels of isolation for every panel.
When you have everything you need, cut the boards to your desired leingth. Cut them all at once! The motto of the day is: mass production!

There are many little things you can do in order to make everything a little faster. Let's say, when marking the boards, where you want to cut them, first mark one very precisely, and then just put the next boards next to it, and you have an instant measurment!
For aestetic reasons, I decided to have the 703 absorbers in a 10cm "deep" frame, so I had to cut them "length wise" too.
When you have all the finnished boards prepared, get 4 "corner hoders" (I am sorry, I have no idea how they are called in english. They allow you to fix two boards, 90 degrees to each other, in position).
Put a little glue to where the boards will come together, fixate them in the "corner holder", and scerw them together. Repeat for all the 4 corners. An even faster way is to have a friend hold the boards together instead of fixing them in the "what-are-they-called holders"