I would not put the attic stairs/ladder assembly opening at right angles to the ceiling joists. You potentially compromise too many of the rafter cross ties by doing that. Instead you should place the cutout opening inline with the ceiling joists/rafter ties. This way you only need to cut one of them to make the room for the rough framing opening.
As evidenced from your pictures of the attic area, your roof support structure is not created from engineered trusses. Instead you have open rafters that depend almost completely on the rafter cross ties to triangulate the rafter structure and keep the building side walls from spreading out at the top due to roof loading. This is the reason why you want to minimize the number of these cross ties that you end up cutting into.
This also means that you may need to be a bit more flexible as to where you locate the rough opening relative to what is built below the attic ceiling. It is often considered optimal to place the attic stair access in a hallway. The consideration of the rafter tie direction and subsequent placement of the attic stair location may very well place some constraints on where the stair opening can be located. That may end up placing it in the ceiling of a bedroom for example.
Another thing to consider is to make sure that you are able to orient the attic stair so that it comes up at its top in a location that has plenty of head clearance under the rafters. This may very well mean that the top of the attic stair needs to face toward the center of the building structure where there is the greater overhead clearance to the rafters.