...well what I had was a hand tied bouquet of ivory roses and the florist did a wonderful surround thing with dried lavender and seashells. The bridesmaids had ivory roses and lavender bouguets and the corsages and buttonholes were ivory roses and lavender too.
I think hand-tied bouquets look best, especially with a dress like yours (not that dis-similar in outline to mine). And picking a theme and sticking to it is nice, but yours should be the most special bouquet!
I had one (expensive) florist do all of the above and then someone else organied the church flowers. remember to take pictures (or even material samples) of your dress and the bridesmaids dresses to the florist and decide on any themes you are having beforehand - for us it was the colours ivory, pink and lilac, lavender everywhere and the fact that we were having the receoption by the sea!
Also, have a good chat to any florists you're considering before committing yourself as your bouquet is a very personal thing and you want it to be better than perfect. My florist picked up on loads of stuff I didn't tell her and my bouquet was a dream bouquet!