1) You can use sweetened shredded coconut, but why add extra sugar when it really doesn't need it! Using unsweetened makes it slightly healthier WITHOUT affecting the taste. I used Kroger Brand Unsweetened Shredded Coconut.
2) Nestle La Lechera sweetened condensed milk brand here is important! Most sweetened condensed milk is less sweet and less viscous. This one gives the full flavor and consistency that you want. If you are using carnation, I would use sweetened shredded coconut instead.
3) Private Selection chocolate chips are the best for melting. They give a smooth consistency when melted. You can also use melting wafers or your favorite chips for melting. Note, not all chocolate chips melt well and become clumpy. Also, the wafers give a thinner layer than melted chocolate chips, so if that is your goal use wafers.
4) You can use food coloring to give a nice color to your white chocolate macaroons.