Can''t decide which diamond to put in setting! Help, plz.

[layla5]

I finally found a setting that I LOVE, but I can''t determine which diamond to place in the center. i have chosen 3 orange/y yellow emerald cuts. I have a link to a picture of the setting below:

http://www.helzberg.com/nav/i/category/jewelry/rings/engagement/1ct+diamond+engagement+ring+set+1651849/r/center+gemstone+shape/emerald+cut/n/4294967252.do?sortby=ourPicks

I don''t know which criterion to weigh my decision on: color, cut, size. Would length to width ratio be considered cut? because that is an issue too. How rectangular does it need to be in order to look good.

Thanks in advance.

 

[layla5]

here are the links to the stones I am looking at:

dnea.net/ye11
dnea.net/ye07
dnea.net/ye08

and I''m also considering getting a more squarish halo for a princess.
dnea.net/yp01