Active job

Large Pergola

I have an outside patio which is approx 4m wide x 9m long. I want to have a Pergola built over the patio to provide some basic shade & shelter (not wanting it to be watertight) We have a span of sliding doors which are 5m long and do not want to have upright supports directly in front of the opening (aprox 3.5m wide), so, we would want advice on design as well as the build. We're open to suggestions around how it might be built & what materials.