Church isn't that slow, although he isn't a big base stealing threat. Byrd had 32 stolen bases in Double A Reading in 2001, so we know he has some speed. Carroll has stolen bases before. So when Nick Johnson comes back, those guys could fill that role.
Personally, if they could pull it off, I would try to pry David Newhan from the O's. They don't seem to need him right now (with him being in Triple-A Ottawa), so maybe a trade could work. Newhan is really fast and can play almost anywhere.