The 100k resistors are the most important. You could use all carbon comps for the 1/2w and 1w resistors and probably be fine. Look at all the great sounding vintage amps that are that way. Or, you could start with all carbon film and then change out the 100k resistors to carbon comp and see what difference it makes. That’s one of the cool things abut building your own amp, you can fuss with it even after its “finished” and see how changes work out. The Two Stroke is such a great little design, you’re gonna dig it. Good luck.