Make sure you have some adjustability in the bike. The saddle should be able to move for and aft enough to accomodate fit "changes". An adjustable stem (like the Ritchey Adjustable or even better, the Look Ergo Stem if you can afford the price "gasp") will allow you to raise or lower the bars as you perception of comfortable changes.
Chances are you will start out in the "short and high" position and gradually move toward the "long and low".
I really think that clubs or shops could provide a service by renting out the Look Ergo Stem (it adjustable in height and length because it has 2 joints so it moves like a raised snakes head) untill a rider is comfortable and then replacing it with the appropriate fixed stem.
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