Well, if you'd rather not head to the store and have sufficient basics on hand we can just go with that for now. But I'll give you an alternative should you have the time and desire to toast and grind chilies (you'd need a grinder as well, like a coffee grinder).
First, I do not include salt in rubs. What I do is salt the meat first--in this case the ribs, both sides--then allow the meat to sit and the salt to draw some moisture to the surface, about 7-10 minutes. Then I apply the rub over the salt. The moisture the salt draws will help the rub stick. Salting separately allows you to apply as little or as much rub as you wish without affecting the salt level as it's already there.
If the ribs are not yet trimmed and you plan to trim them, do so tomorrow and get it out of the way. Pul on a platter or sheetpan, covered, then retun to the fridge till Sunday. (Remember to remove the membrane.)
For salt, what I do is imagine the meat already cooked and placed in front of me but unsalted. How much would I apply were this the case? That's what I sprinkle on, then flip and do so again (a bit lighter on the bone side). These sit while I make the rub or get the coals going for the Minion or whatever, about 7-10 min, then I apply the rub.
How about:
6 T chili powder
6 T light brown sugar or turbinado
1/4 c granulated garlic
1/4 c granulated onion
3 T thyme
2 t rubbed sage
1 t ginger powder
1 t ground black pepper
1 t ground coriander
1 t ground allspice
.5 t marjoram
.5 t cayenne (or less or more, depending on desired heat)
.5 t ground white pepper
.5 t ground cumin
.25 t ground clove
What do you think?
(Alternatively, get anchos, guajillos, cascabels at the store then toast and grind a few of each. Measure out 2 T of each ground chile, blend and taste for heat. Up the heat, if desired, by including the cayenne noted above, in whatever quantity is suitable.)
