I recommend posting in the very active Amaryllis forum. They know their stuff!

http://forums.gardenweb.com/forums/amaryllishippeastrum

Amaryllis only flower once per season and if you cut off their flowers, then you are done for the year.

My plebeian understanding is they create the flowers deep in the bulb months before they actually bloom. So, they can't just generate more flowers on demand like other plants would.

Definitely check out the forum that SoCal gal suggested. There is a wealth of information and you can see what might benefit for next year's blooms.