In regards to suiciding - yes, you can put more than one group, even if you didn't attend their pref -- BUT, keep in mind that if you put down those groups, and one snaps you, you are OBLIGATED to that chapter for an entire year, regardless of whether or not you accept their bid.
A con for suicding is (thanks to whomever put it in such great words) you could've been cut by a tiny margin as previously stated -- and putting down more than one may help you get a bid.
But, on the other hand, if you know that you will only be happy at one place, then you must go with your heart. It will serve no purpose for you to put XYZ down first, and ABC second -- only to have XYZ decline you and ABC pick you up.
So its a gamble - one is a much safer bet as far as numbers go, but the other is safer for your emotional state! I just can't wait to hear all about it