Thanks! I totally agree with you regarding the architect. My only concern is that the scope of services (and the associated quality) vastly varies between landscaping companies so I thought going with a landscape architect would be safer (but definitely more expensive). Because we're not very knowledgeable about this whole process, what we want to avoid is hiring a "traditional" landscaping company faking / overselling their experience in hardscaping when in reality they mainly do more traditional work (mowing, pruning, planting, etc.).

Very good point regarding the water table, this is something we need to check. We do have a sceptic and we know where the tank and field are.