You do not need to garden on top of a hill or mountain to have an Alpine garden but it helps.
Alpine plants tend to have deep roots and a deeper dislike for wet around their necks. Many alpines are bulbs and use other tactics to survive harsh conditions. For every generalisation there is an exception and this book gives you a better insight into Alpine plants.
Success with Alpine Gardening by Graham Clarke
The Alpine Garden Society is one of the best organisations that I belong too. Their seed catalogue contains thousands of varieties that members can obtain for free or nominal amounts. The magazine is both travelogue and garden informative. Give the AGS a try