Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
I think that you might be able to find 7-speed Sora levers. Otherwise you'll be looking for used or NOS stuff.
Whether or not 8 speed STI's will work with a 7-speed cassette depends on how picky you are. I've gotten them to kind'a work, but they don't index perfectly. You'll probably find that you have to double shift in some situations.