Steel workshop/shed ideas

Hi folks,

Planning on building a 3m x6m shed on existing concrete at the back of the house. Thinking of using 40x40x3 box for the frame, and 40x40 angle for trusses/supports. Undecided whether to go for a lean-to design for simplicity, or A-frame Gable end for the aesthetics. Will divide it in 2; half for me and my welding escapades, the other half for my son to tend to his chickens etc.
Any thoughts? Advice? Planning on having a double garage style door at one end, and a single door and possibly a window on the other. Using corrugated sheets for cladding the walls and roof, probably use plenty of corrugated perspex sheets on the roof for light....
Anything I should be aware of before I go ordering box section and cladding sheets?