Since your original post makes me think you don't have any kega yet You could just start your homebrew with Sanke kegs in the first place. No adapters needed. Plus in a pinch at one you can always grab a local brewery keg and hook it up
A starter just gets the fermentation going faster. You can pitch most modern yeast straight from the package. It might take 48 hours for some bubbles, but hey waiting is part of the game.