Based on my experience in a lot of circuits that I have made, there would be no problem in using resistors and capacitors by 2.5 GHz and even more above. ( I have used 0603 resistors by about 6Ghz and by removing their metalalization in parallel faces by above 10GHz).
But I strongly recommend that you use the smaller size (0603 instead of 0805 size).
If you have any data available or any measurement devices, for capacitors the series resonance frequency is the maximum reliable frequency that they may be used.