I actually had one a lot like that that I found in a bridal shops jewlery case. It was perfect because it isn't like a regular tiara that has to stay in the shape it is in, but it flexible. I would check with local bridal stores to see if they carry anything like it. The store I got mine from had just gotten it and wasn't totaly sure what it was. Here is a picture of mine.
It did cost more than a regular tiara, and more than I wanted to spend, but I loved it to much to pass up. Oh you can also try ebay, etsy, or bravo bride
I think this is a headband style tiara... at least, that's what I plan to use to get this sort of look. They are flexible and usually have little loops at the ends to put hairpins through to fasten it into your hair. I got mine on ebay for around $50... I think they actually have more of this same one, but obviously you could just do a search and find a ton of them!