Been a while, but I'm finally getting it done, have simplified the designs a lot.
I 've bolted two 2"x6" beams to the ceiling (3m30) and the floor at approx 93cm (3 ft) from each other
Pull-up bar @ 2,3m (7,5 feet)
J-cups
(and I'm pretty proud of having figured that one out) that I can put at 1" (2,5 cm) intervals. I have drilled a hole for 12mm (1/2") bolts every 2" (5cm) in the vertical beams. In the J-cup, also at 2", but with a 0,5" offset from the center.
This allows me to have two heights with a 1" difference on every position by simply turning the J-cup 180° around.
Next : finishing touches, storage and flooring.
Just wanted to share.