What I normally do in this case is
- Import the model in Blender 2.79 then save the file.
- Open the new Blender 2.80 project and go to File -> Append menu.
- Navigate to your previously saved project with the imported model in 2.79. When you select the
file you may need to wait a bit for all the folders to show up.
- When all the folders populated then click on the Object folder, may need to wait a bit to populate, and
select all the objects here that you want in your new 2.80 project
and click on the Append from Library button on the top right.
All the selected objects should appear with the correct materials in your 2.80 project.
In case you still would not get the materials and textures, very unlikely, then go to the File -> External Data menu and select the root directory of your 2.79 project file. Blender will automatically search for the related textures and materials and add them to your 2.80 project. This later is also good when you moved a project file and after reopening the textures and materials are gone because the path has changed. This way you can get Blender to search for them, you just need to point it to the right direction, so to speak.
Unfortunately I do not know an easier solution to export 3ds files from 2.80 but this process can be reversed and exported from 2.79. On the other hand I think you should be fine to export obj file from 2.80. It is supported in nearly any good software.