Rinse rice in cool water until water runs clear; drain well. Place rice and water in 1-quart saucepan. Heat to boiling; reduce heat to low. Cover; simmer 20 minutes (do not uncover). Remove from heat; let stand covered 10 minutes. Place rice in glass or plastic bowl; stir in vinegar. Set aside.
Cook spinach in microwave as directed on box. Drain spinach; cool 5 minutes. Carefully squeeze with paper towels to drain; set aside.
In small bowl, mix crabmeat, cumin and sea salt; set aside.
On each tortilla, spread 1 tablespoon of the taco topper. Spread 1/3 cup rice mixture over half of each tortilla (if necessary, wet hands with cool water to prevent sticking). Top rice with 1/4 each of spinach and crabmeat mixture. Place avocado and pepper strips down center of each tortilla; sprinkle with lemon juice. Starting at filled side, carefully and tightly roll up tortillas. Wrap each tortilla roll-up in plastic wrap. Refrigerate at least 1 hour or up to 4 hours before serving.
To serve, trim ends from roll-ups; discard. Cut each roll into 8 even slices. If necessary, secure with toothpicks. Sprinkle cut sides with sesame seed. Place roll-ups on serving platter with small dish of remaining 1/2 cup taco topper; garnish with cilantro sprigs.