This is my first time (and hopefully only time

I''ve been giving thought to proposing to my g/f of 7+ years possibly during Christmas or New Years. My only problem is that I cannot decide on a ring. I know she wants white gold or platinum, something unique but still somewhat traditional, she likes the diamond to be the highest point/main focus (no bezel mount, or 3 stone), and she likes sapphires but not as side stones.
I''ve asked her to pick out a few that she likes, but she changes her mind a lot & they all seem to be vastly different.
Her choices (in the order she placed them):
Reflexxions by Jem Braggik:
http://www.wdcgroup.com/jewelry_reflexions.html
This Pave style platinum ring here:
http://www.diamondsonweb.com/shopping/sdetail.mhtml?c_gid=6;cat=12;sku=1390
The channel set/cathedral here:
http://www.bluenile.com/product_details.asp?oid=5848&page=1&show_all_pages=1&col=3&row=3&pos=9&set_shape=
I''ve been looking for one that will surprise her and somewhat mix the styles & types that she picked out. I''ve looked through hundreds (probably thousands) of rings, but cannot make up my mind. I''m afraid of picking out something that she will pretend to love but really would have preferred something else. My budget is unfortunately only around 5-6k total.
A couple that I''ve seen and liked but have slight issues with (she has not seen these):
http://www.pearlmansjewelers.com/jewelry-designers/beverley-k-jewelry/rings/27PP1 I really like this ring, but question whether the sapphires maybe to much like side stones to her? The band is higher priced than most of the others, it wouldn''t leave as much budget for a diamond. Also, I doubt this one could be delivered in time for Christmas or New Years..?
http://www.abazias.com/database/NewEngagementInfo.asp?stock=ENG-SS-12-7505 Don''t like the fact that it can only accommodate a 1/2 carat, I was hoping for something a little larger. Also, their terms don''t seem to be quite as good as some of the other sites.
http://diamondsonweb.com/shopping/sdetail.mhtml?sku=1281&cat=12&x=45&y=63 Doesn''t really match any of the ones she picked out but I think it is nice.
http://www.pearlmansjewelers.com/jewelry-designers/spark-jewelry/rings/51MM1 Again doesn''t really match any that she picked out but very nice - a higher priced band though it wouldn''t leave too much for a diamond.
I apologize for such a long post, but would really appreciate everyone’s thoughts & opinions.
If I’ve posted in the wrong section or was not supposed to provide links, please delete and I will repost appropriately.
Thanks in advance.