Preheat oven to 350°F.
Stir together salt, pepper, cumin, chili powder, and cinnamon, then coat pork with spice rub.
Heat oil in an ovenproof 12-inch heavy skillet over moderately high heat until just beginning to smoke, then brown pork, turning, about 4 minutes total. Leave pork in skillet.
Make glaze and roast pork:
Stir together brown sugar, garlic, and Tabasco and pat onto top of each tenderloin. Roast in middle of oven until thermometer inserted diagonally in center of each tenderloin registers 140°F, about 20 minutes. Let pork stand in skillet at room temperature 10 minutes. (Temperature will rise to about 155°F while standing.)
Make vinaigrette while pork roasts:
Whisk together juices, mustard, curry powder, salt, and pepper, then add oil in a stream, whisking until emulsified.
Prepare salad ingredients while pork stands:
Cut peel, including white pith, from oranges with a sharp knife, then cut oranges crosswise into 1/4-inch-thick slices. Toss spinach, cabbage, bell pepper, and raisins in a large bowl with about 1/4 cup vinaigrette. Halve, pit, and peel avocados, then cut diagonally into 1/4-inch-thick slices.
Cut pork at a 45-degree angle into 1/2-inch-thick slices. Line a large platter with dressed salad and arrange sliced pork, oranges, and avocados in rows on top. Drizzle some vinaigrette over avocados and oranges. Pour any juices from skillet over pork.