Prepare the kebabs: Whisk the olive oil, vinegar, paprika, cumin, brown sugar, garlic and 1 teaspoon salt in a large bowl. Cut the beef into 1 1/2-inch pieces, add to the bowl and toss with the marinade. Cover and refrigerate at least 2 hours.
Meanwhile, make the salsa: Mix the tomato, bell pepper, onion, olive oil, cilantro, vinegar, 3/4 teaspoon salt, and pepper to taste in a bowl. Make the chimichurri: Puree the parsley, cilantro, olive oil, garlic, lemon juice, 1/2 teaspoon salt and 1/4 teaspoon pepper in a blender. Transfer to a bowl. Cover and refrigerate the salsa and chimichurri until serving.
Preheat a grill to high. Thread the beef and sausage onto skewers (keep the meats separate), leaving a bit of space between each piece. Brush the kebabs with olive oil.
Brush the grill with olive oil. Grill the kebabs, turning, until charred and cooked through, 6 to 10 minutes for the beef and 10 to 12 minutes for the sausage. Transfer to a platter and let rest 5 minutes. Season with salt and serve with the salsa and chimichurri.