Dear God.
You expect people to let you cut them open and you can't pack your shit for a trip?
I don't know where you're going, and like you said, every hospital is different. At most places, you'll probably be in scrubs all day, so even if you have to enter and leave the building in dress clothes you can get away with bringing only a few shirts/ties/dress pants. Obviously, try to get program-specific advice. The residency coordinator is usually a good resource.
As for scrubs - sure, bring a couple pairs of your own, but realize that it is a JCAHO requirement that only hospital-issued scrubs that in theory you put on right before you enter the OR are allowed. So, the hospital basically has to give you scrubs regardless of what the secretary who runs the scrub pixis says.