Thread shrimp onto 6 (10-12")metal or bamboo skewers. (If using bamboo, soak in water 20 min.) Then insert 2 skewers into each shrimp to keep them from slipping. Arrange kebobs in shallow baking dish. OR you can skip this step completely and use a grilling basket (or foil) instead.
In a food processor, combine cilantro, chiles, onion and 3 garlic cloves; finely chop. Gradually add all remaining marinade ingredients, processing until bright green paste forms. Pour minture over shrimp. Cover; refrigerate 30-60 min., turning several times to marinate evenly.
Melt butter in small saucepan over medium heat. Add 2 garlic cloves and cilantro; cook 2 minutes or until garlic just begins to soften, stirring constantly.
When ready to serve, heat grill or broiler. Drain kebobs and discard marinade. Place on grill over med heat or charcoal or broil 4-6" from heat 2-3 mins on each side or until shrimp turn pink, basting with garlic-cilantro butter. Serve with lime wedges.