I am a GIS expert with over 10 years' experience in designing PostGIS databases and spatial data management.
I have designed database schemas for a variety of spatial data - including Ordnance Survey products (the UK's national mapping agency), and seazone (marine maps), so I am very experienced in developing databases to hold different data formats, and I know the importance of spatial indexing to improve performance, and the use of primary and foreign keys, and other constraints to ensure data is correctly entered into the system.
I assume PostgreSQL is the database system you would like to use (also my preferred option), and I would propose making full use of the PostGIS raster functionality since you refer to DEM and imagery.
It would be interesting to know what you intend to use this database for as this will also help the design process, but since you mention point clouds, that suggests you will have quite a lot of data, in which case table inheritance, and declarative partitioning (in PostgreSQL 10) will help ensure scalability as much as possible.
I am not sure from the project description if you also require the data to be loaded into the system - if this were the case, I would expect the job to take somewhat longer, and I would prefer to discuss this with you additionally, but as a start I would say I would use gdal/ogr2ogr tools to carry out this part of the work.
As you will see I am new to Freelancer, so I thank you for your consideration,
Fiona