I like the emerald cut better on your hand. You have great hands and the squarer shape of the rectangle of the stone works to echo the strength and shape of your hands.
I'm with AME and others here. If you can, and it is possible, consider looking elsewhere as well to be sure you get the best stone for the cost and the highest quality.
White gold tends to need refinishing over time, you may want platinum if you can afford it.
Also smaller local jewelers who want/need the business (reputable of course) might have incentive to work out a good price for you as well. I'm sure tPFers in your area might have jeweler recommendations.
Either way, this is a very exciting time and I wish you much happiness!
But...do look around.
Whiteflash.com bluenile.com for stones -- then find a setting.
Also, don't forget Costco! Not super romantic, but they are getting a good reputation for diamonds.
http://abcnews.go.com/GMA/Moms/story?id=1197202
Just a sample from Costco, your local store may have different inventory:
http://www.costco.com/Princess-Cut-...ing-(2.00-ctw)-Platinum.product.11607006.html
But that is platinum with a 1ct center stone, 2 ct overall for $7499.99
I know it's a bit weird and unromantic to go to Costco, though.
You might also try Empire Diamond:
http://www.dialadiamond.com/
Best of luck!