There are couple harder to find parts on the Pepper Spray and I'm wondering if I can make effective substitutions. The 50n caps I would replace with 47n. And the 47u tantalum cap, I'd use a 47u electrolytic cap. Any ideas if these subs will work out ok?
I can't see any reason why they wouldn't work. The 47n for the 50n is going to be an inaudible difference in frequency response. The 47µF electro for tantalum might actually make a little difference in the sound. If you can use a low ESR electrolytic in place of the tantalum, it should actually be better.
I've seen people use regular electros instead of tantalum. In fact I think Frederic Effects used them on his production model Percolator. They may sound just slightly different, but not in any deal breaker kind of way.