Aleppo pepper looks a bit similar to crushed red pepper, except that it is without seeds and is moister. It has a little heat and a wonderful slightly sour fruity chile flavor. It is named after the town in Syria where it originates. It is also grown in Turkey. I go through a lot of it, using it on and in egg dishes, to top homemade pizzas, and in numerous rubs (I am partial to the flavors of the Levant and Middle East).
Amchur (also spelled amchoor) is the dried, powdered version of unripe mango. It is also sour and quite fruity. It is found in some regional Indian cuisines.
Sumac is another fruity, sour flavor. It is used in and on many dishes in the cuisines of Lebanon, Syria, Turkey and Persia. It is a common tabletop condiment alone, or mixed with thyme and sesame seeds for the vary popular condiment known as zatar (which is sprinkled over cooked rice, on meats just off the grill, on lightly oiled and grilled flatbread, etc).
I quite like fruit flavors with grilled, roasted and/or smoked meats. The above three combine well with various herbs and spices, alone or mixed with each other, and offer good counterpoint to sweeteners, whether used in the rub or in the accompanying sauce.
Penzey's carries Aleppo and sumac. There might be Canadian sources that would be cheaper, shipping-wise. Seek amchur in Indian markets.
Proportions can be varied, depending on use but as examples:
2 T thyme; .5 T Mediterranean oregano; 1 T granulated garlic; 1.5 T granulated onion; 2 t ground white pepper; 1 T Aleppo; 2 t ground corinader
for the second, 1 T of each
4 T ground NM hot chile, guajillo, cascabel, or a blend; 3 T granulated onion; 1 T granulated garlic; 1 T thyme; 1 t marjoram; 2 t rubbed sage, 2 t sugar; .5 t Ceylon cinnamon; 2 t each amchur and sumac; .5 t each allspice, ginger and coriander; .75 t each crushed black and white pepper
When and if you hit an Indian store (or a Mediterranean one) grab some pomegranate molasses. It is excellent as a flavor agent in many sauces that work well with the above, and is also a good addition to more typical Q sauces.