Whatever you do, don't mix your blues. I would stay with flowers as close to the turquoise as possible.Silk flowers will be easier to match than live flowers. Specially died live flowers will be extremely expensive and theres no guarantee that they will match. Yellow and white would also go well with turquoise. A smaller bouquet is classy. You could also order extra ribbon the same color as the one on your dress from the dress manufacturer to use in your bouquet. Good Luck, and Congratulations.