Congratulations on your Twinkles - what a cute name !!
Here's some grooming help and a good shampoo may help with the hair -
http://www.ytca.org/grooming_clips1.html
The only experience with products I have are the Chris Christensen Systems -and Plush Puppy products - you may want to check into these -
I groom my girls myself now after not being able to find a good groomer and find if you study other yorkies - you can follow the lines of the cuts they have.... OR.... go to a good groomer - write down what you want done and hope for the best !