Here's a little update for you guys (for those, who are interested):
The decisions have been made with regards to component selection. For the first prototype, the team isn't concerned THAT much about size and cost, since we have a supplier. Thus, for the first product, the device will consist of:
-9V battery to power the uC;
-A little mechanical power switch;
-Arduino Uno, as the main microcontroller;
-HC-05, as the BLE module;
-DHT11, as the humidity & temperature sensor;
-BH1750 for light intensity sensing;
In the future, though, if we are able to make a nice working device, we will reduce the size of the uC. That would be done by programming an 8-pin ATtiny chip using the Arduino Uno (the size of the entire product shrinks considerably).
A mobile application is being programmed as I am typing this post, and at the moment I can only allowed to show you these screenshots (see attachments), which depict the very basic of the basics, haha.
As for the project itself - I am learning so much and am so glad I can be a part of it.