The Laker fans do have a lot of love for their team, too bad some of them had to get out of control.
The beach party is fun for everyone. But like I said don't make it a habit. Girls are'nt stupid. You guys still have to do your jobs and rush the guys.
The girls don't have to be from any particular sorority or greek at all. Just invite girls whose opinions you trust. If they say the guys are jerks or something you probably don't want them.
These kind of parties are great to have right before sorority formal recruitment starts. The girls get to blow off steam AND practice their rush skills. Just treat it like a regular party it'll be great.