Warmoth turns out good parts with many happy campers. Before you pull the trigger there, at least consider USACG, MusiKraft, Allparts, B Heffner, etc. The first two offer more options (like clay dots and 50/50 side dot placement like you’ll find on the Black 1), and the latter two will get you about what you want for the regular Signature but for a lower price.
Obviously, “Thick C” doesn’t give us the dimensions. You’ll need to do some more research from users to see if anyone has published measurements on theirs or just wing it with something other than thin C.