RTK with different Base and rover receivers

Hi guys,
I am using Mission Planner with EMLID NAVIO2+. I am trying to arrange a RTK configuration as an experiment. I have survey grade GNSS receiver E600 of E-survey as a base station (as some from Leica and Trimble too). It provides multi frequency and phase data from GPS, GLONASS, BEIDOU etc… I connect it via serial cable. Mission Planner shows everything right in the Injection window - the messages, the satellite graphs and for the last example the Base, GPS, Glonass and Beidou markers lighted in green.
At this experiment I am interested in the possibility of connecting Base and Rover from different producers. I am in the process of purchasing the Rover receiver and I am hesitating between Trimble/Septentrio or some cheeper solution as Picsi or Sirius. At this moment I am not very interesting in RTK. More important is to have 1 cm precision of the camera position and it is better be in PPK.
I will appreciate any advises on this.
Thank you