I was going to use fake petals, but my wedding was outdoors and I didn't in the end because when I tried it out, they looked really tacky in the outdoor light!
I bought mine off ebay, and I'm not sure if they were silk or not. In the end, we bought 24 little flower pots with red and yellow flowers from a local nursery which was having a special, and sneakily plucked some roses from a roundabout near our house. Not a full look like you've got there, but it looked nice nonetheless! I can send you a photo if you like.
If you do wanna try out the fake petal thing, I have a heap of the burgundy and cream ones that I didn't use. PM if you want to discuss.