If you’re interested in Sichuan cooking, I just came across this cooking book...it’s supposed to be one of the best for Sichuan recipes and it’s much more reasonably priced than a lot of others.
Have you tried the one at taste of chungdu? Even better in my book. I've cooked the version from Fuchsia Dunlop's sichuan cookbook and was pleased.
How do you use them? so for something like the mala spice mix whole spices are fairly cheap and most sichuan recipes call for whole spices anyways even if you toast them and grind them.
If you want something for lazy cooking you could make a spice blend by toasting then grinding dried chilies and sichuan peppercorn then adding however much salt, msg and whatever other spices you want so you could use it like a taco seasoning pack.
If you're interested in learning to cook sichuan food I would check out The Food of Sichuan
50Hertz makes a really great quality pure Sichuan peppercorn oil - they actually have a green and a red peppercorn oil, as the two have differences in flavor. These are just pure Sichuan peppercorn oil, no spices or chilis.
Blank Slate Kitchen makes a Sichuan Chili Oil - in addition to the peppercorns and chilis, it has a number of other spices as well.
If you're looking for a Sichuan cookbook, The Food of Sichuan by Fuchsia Dunlop is probably considered the best out there (in English at least). Red Hot Kitchen is great, though not strictly Sichuan.
What /u/eobanb said.
I'm reading through the updated version of Fuschia Dunlop's (who is sort of like the Julia Child for Chinese and particularly Sichuan food) book now where she talks about the spread of popularity of dishes from Sichuan and a lot of the development of those dishes and flavors that define the culinary style about a century ago, when there was a large population influx into the region.
The book is here if you're interested in the subject: https://www.amazon.com/Food-Sichuan-Fuchsia-Dunlop/dp/1324004835
As a hobby, I like to try to recreate dishes I've had while traveling or from restaurants, and I have been focusing on Sichuan lately.
My understanding is also that most of the people who wound up in America were from those coastal provinces. I had heard (and never confirmed) though that the original owner of Chow Bar was from the northern interior area, and might have been a famous singer/performer back home.
Fuchsia Dunlop is your new queen. She is the authority on this.
For your specific request? https://www.amazon.com/Food-Sichuan-Fuchsia-Dunlop/dp/1324004835