Good luck to you! I hope you have a great experience with recruitment and try not to stress too much.
As you probably know, since UGA's admissions requirements have gotten higher and higher, having high grades isn't going to set you apart from the others girls going through recruitment as much as maybe it would have back in my day. You also probably know that other students admitted also have great extracurriculars, activities, and involvement. It doesn't mean that it's not awesome that you have your resume, but you can't expect it to distinguish you as much as it would have at one point in UGA history.
The main thing with recs is to contact an alumnae panhellenic in your area for which you have already been given a link. Even if you miss the published deadline for recruitment help, it's likely that someone will still be willing to help you if you make contact now.
The other big resource for recommendations are probably some of your teachers. Especially if your teachers weren't fresh out of college, you probably don't which were in sororities, but if you will contact some by phone or email, you might be surprised at the number of women you already know who are NPC alumnae and the number of people they can put you in touch with.
As someone above noted, you really do want to get in touch with girls you already know who might be greek at UGA. They will offer you practical advice with getting ready for the process and may have leads on recommendations.
UGA is a weird place to rush and try to keep in mind that some stuff isn't in your control. Don't get your feelings hurt if you don't get some of the invitations to later rounds that you want. Hang in there and consider which of the groups you like best as you get into the later rounds of recruitment. If you keep an open mind and stay positive, there's a really good chance that you can find a group that you really like who really wants you as a member.
ETA: in response to your particular questions: I've heard that no group cuts based on recs. I can't image how anyone could know that, but a Greek Chat poster who served as a recruitment counselor one year said that is what they were told. Personally, I wouldn't chance it, and I'd put as much effort as I could into getting recs for all the chapters. I don't know if you really need four or five, but having one for each is probably pretty important.
For everything else, read The Pointer:
http://www.uga.edu/panhellenic/forms/POINTER2008.pdf
It's the official UGA Campus Panhellenic guide, and ask a girl who went through last year. We can all tell you what we'd like to be true and what would be common sense, but that might not have anything to do with how things actually go down.