Available locally would likely be anchos, guajillos, cascabels, negro pasillas, chiles de arbol and probably chipotles. (I don't use chipotles in many rubs for smoked meats but, rather, in rubs for fast-cooked grilled stuff. It adds smokiness when fast cooking is likely not to. Same with smoked paprika.) You might need to hit a Whole Foods for the chipotles; maybe not.
Aleppo and aji amarillo are my favorite chilies. Aleppo is available from.
Penzey's and
WorldSpice and
The Spice House. Other spices are, of course, available at these sites.
Whole and powdered ajis as well as other chilies are available from
Sweet Freedom. I know they were recently out of ajis. Not sure of the staus now. The chilies available locally will get you going.
The arbol have heat but zip for flavor, like cayenne. The chipotles will have a bit less heat but smoky flavor. The guajillo has pleasant medium heat (usually) and some darker, fruity flavor and ancho has fruitiness, vegetal notes and pretty much no heat (a good replacement for paprika which is near flavorless in rubs). Cascabels have some heat and berry fruit notes and negro pasillas have full fruit flavor and not much heat.
Aji amarillo and Aleppo have moderate heat and both have full fruity flavor with lots of higher chile flavor notes.