You can in fact get one of the Kanto starters in Heart Gold and Soul Silver.
First you must of completed tr Elite Four, and made your way through the Kanto region. (I'm not 100% sure if you need all sixteen badges or not, but you probably do)
Go to the top of Mt. Silver, and defeat Red at least once.
After you defeat Red, go to Pallet Town and speak to Professor Oak in his lab, where you'll be able to get one of the three Kanto starters.
*Keep in mind you can only obtain one of them.
Hope this helps! ~