If you look at the options page, there are many Sunface versions with different silicon and germanium transistors. I built one with high gain silicon, and another great sounding one with a pair of low gain Russian ones.
There's a newer Sunface with (different model than what I used) Russian transistors called BART. With the Sundial, it's a very forgiving circuit, and just about anything you put in there reasonable will work.
Although it was a long wait to my country, I bought dozens of Russian transistors off ebay in one purchase based on friend's recommendations and they've worked well in Fuzz Faces and Benders. I've also bought Fuzz Face and Tone Bender sets (one was an AC125 set from diyguitarpedals,but it was years ago) already measured for me before, and was able to get the same results after spending time auditioning my newer Russian batch.
I was kind of thinking I will not be using fuzz in high gain. I would rather have it be a bit too low in gain and required a boost pedal rather than too much if that makes sense.