For my wedding, I wore a Vera Wang bridesmaids dress in off-white; they had it as a try-on model at a wedding store. It was simple, beautiful, and very reasonable! You might try a couple of wedding stores just in case they have something similar. I also have a friend doing her wedding through J Crew; they're more than I would spend on a regular dress, but they have some really pretty ones that you could wear for a wedding for $2-300 dollars.
I, too, have curly hair, and would recommend Leslie Chenault at Balise salon on the square in McKinney. Her hair's curly, too, so she'll know what to do!
Finally, for flowers, you might try a local farmer's market. I did this for my sister's wedding (in Michigan). We got a lot of beautiful, very fresh flowers for very cheap, then did the arrangements ourselves.
Congratulations on your wedding, and on keeping things reasonable! As our pastor said to us when we married, a wedding should be a celebration, not a spectacle. It sounds like you have your priorities in order to start a great marriage!