if she's a hopeless romantic like you said.. then she'll appreciate the extra effort you spent contacting the florist in her home town, rather than doing something online and impersonal.
i'd also suggest calling her about 30mins to an hour after she is due to recieve them. really let her know your thinking about her
really i'd suggest going through a florist local to her. less likely to have something get lost in the mix somewhere. you get to deal with an actual person when describing what you want, and it does seem more personal somehow. i'm sure she'll love it no matter what you decide to do though