Hello!
I'm a 3D game artist, and I've used Unity for most of my game projects. I currently model in Blender 3D, but I've previously worked with 3ds Max, and I can export the models in file formats and scale compatible with 3ds Max.
You mentioned you prefer minimum amount of furniture & a low-poly model. I have experience in real-time modeling including both mobile and desktop PC projects. I believe it'd be better to first discuss your needs, and design the best scene to fulfill those needs. This would include list of details about the space, about the needed furniture, and about what sort of polycount and amount of detail would fit your intended use, what sort of style and Unity material you prefer, etc. After that, I'd move on to the actual modeling as a separate milestone.
I will be attending a game conference next week and need to prepare for that. If you're in a hurry, I may not be able to accomodate your schedule.
best regards,
Janne Joensuu