Complete set for RTK

I just started getting into RTK and I am not sure what I have to get to have a working RTK setup. I am working on a student project that used Pixhawk and PX4.
As I understood it so far I need the following things:
2x 3DR SOLO GPS (NEO-M8P), one for base and one for rover.
1x Tiny RTK GPS (NEO-M8P Base)
1x Tiny RTK GPS (NEO-M8P Rover)
2x Telemetry module (one for rover, one for ground)

The GPS modules get connected to the Tiny RTK modules. The Tiny RTK modules need a 5V input and need to be connected to Telemetry. Is that correct? Is it also possible to connect the Tiny RTK module to the Pixhawk, get power from Pixhawk and connect the Telemetry module to Pixhawk?
To which port does the Tiny RTK have to be connected on Pixhawk?
I don’t need another GPS module next to the one connected to the Tiny RTK module on the drone, right?

Another question: The student project I am working on aims to build a drone that can change its orientation while keeping a constant position. This means that the GPS module, which would be installed on top of the drone, could also look to the side or even downwards, depending on the orientation of the drone. Is it still possible to get accurate position data if the GPS module doesn’t point upwards?

You do not need the 3DR solo GPS modules. The RTK GPS modules by Drotek are the GPS devices. Or am I missing something?

If not, 1x Tiny RTK GPS (base) with antenna and 1x Tiny RTK GPS (rover) with antenna.
Alternatively, the XL RTK GPS for either (base-capable modules can also be used as rovers)

I suggest you follow the guide here:

No, connect the RTK GPS rover to the Pixhawk as you would a regular GPS module.

You should expect positioning quality to severely decrease when the antenna is not directed towards the sky. Perhaps GPS is not an ideal positioning method for your project.

Thanks for your reply. You are right, GPS might indeed not be the best solution. I also thought about using vision (tracking an object and keeping a constant distance to it while changing the orientation of the drone).