I hear ya' with the non-traditional wedding. Though, I think mine will be a bit more traditional than yours ~ I just don't want my wedding to be that cookie cutter event that everyone has already been to. I love that idea of the wedding march being done with an electric! Not to sound like Paris Hilton here, but that is gonna sound hot. I also opted not to walk to the traditional wedding march ~ instead we're going to have the song 'come away with me' by Nora Jones, playing. Our first dance is going to be 'I wanna grow old with you' by Adam Sandler lol.
But as far as where to find rock n' roll stuff, I know I-Party usually has some things like that. I don't know if you have any of those in your area though. But try any party store ~ I'm sure you can find stuff like inflatable guitars and mini records that you can use as favors or place cards. You can also try a rental place in your area. They may have props you can rent that fit in with your theme. As for invitations, I can't recall seeing that theme in anyplace that I've been looking, but I'm sure you could find a place that can custom make something like that. Try doing a rock n' roll search and see what comes up for ya'. You'd be surprised what you can find.
I'm a red head too ~ my color scheme is sage green, yellow and ivory. What shade of green is your dress? Maybe for your color scheme you could do green, black and gold or silver. Table cloths could be black with gold or silver chargers and then incorporate green into the centerpieces. The possiblities are endless, just put your mind to it girl. If ya' need any more help, gimme a shout.