Since you gave us an out by saying 'without a lot of sugar' then yes, you can do that. I agree with FATZ and Scotty; the artificial stuff doesn't cut it. But you can cut way back on the sugar if you want. It doesn't take the tongue much to register sweetness. You can help this by augmenting your mix with the 'sweeter' spices and skipping the drier (less sweet) ones e.g. cinnamon, allspice, onion, garlic, coriander, marjoram, thyme, sweet paprika, fenugreek, ginger, have a sweetness about them that doesn't dissipate in heat and that a little sugar will boost. Some you might want to lessen or avoid: oregano, cumin, cayenne, sharp or half-sharp paprika, Guajillo, dried lemon zest, dried jal powder, cardamom, sage. For heat I'd use the fruitier pure chili powders like Ancho (which I frequently use in place of paprika), not a lot of heat but good fruit; Aleppo (wonderful fruit, good heat, but you have to grind it further [it's packaged kind of like crushed red pepper,usually]), and/or chipotle powder (the red kind, made from moritas--it's sweeter than the tan/brown powder made from tipicos which have smoked longer).
Also, you can make sweet sauces using just vegetables and fruits for sweetness.
Hope this helps.