Awesome help guys, thanks to everyone and especially Myramyd!
I've just finished mine now with R5 as 47 ohms and red LEDs in clippers, sounds friggin' awesome.
I've ended up using a MAX 1044 charge pump as the others I had (LTC 1044 and 7660) gave me a high pitch squeal on high gain channel when cranked.
But now it's all sweet! Awesome pedal!
