If you want to SIP (suicide) Aquarius because you know that you won't accept a bid from Pisces or Libra then you should. Your recruitment counselor will be trained to strongly discourage it though. If you've had the chance to read a lot of other threads you might know that she's likely under educated when it comes to bid matching and might mistakenly tell you that "you'll get kicked out of the computer" or something else. If you SIP you won't be eligible to be added as a quota addition. However, if you do SIP and don't bid match you'll still be eligible for COR through out the year. If you list Libra or Pisces, match one and then decline the bid, you won't be eligible till next fall.
Also, I would NOT "try to make not as good of an impression on them tonight". If you know with all your heart you don't want Pisces I would suggest
politely and diplomaticaly telling the girl at Pref that you do not see yourself in their chapter and have your heart set elsewhere. No reason to drop names. If you do something that leaves them with a bad impression, it may get around to other chapters, including Aquarius. That decision may come back to bite you.
Good Luck and listen to your heart!