Wow, Dfran! Talk about focus! It sounds like you all have clarity of purpose and a strong desire to move forward in a thoughtful manner. I am sure that you will be successful in all of your endeavours.
Finding a combination of Greek letters which has not already been taken can be tricky. I would do keyword searches on engines like yahoo and google and see what comes up.
Alternatively, you can visit one GreekChat user's website. Her user name is localsororities and her website is at:
http://www.geocities.com/localsororities/
She has quite a comprehensive list of local groups. You might be able to look there and see how "popular" certain names are based on what combinations of letters you are considering.
Other than that, welcome to the Greek community! If you have any other questions, feel free to post them. I'm sure someone on here will have an answer for you.
Best Regards,
.....Kelly