as for the swap itself, the only thing you have to watch out for is different brackets. we got a KA that we thought was an S13 and didn't realize it wasn't until nothing lined up right, the A/C and power steering brackets are different.... but only sometimes, cuz i've heard that everything is the same too.....
my advice is to just pay attention to details. its not a hard swap as long as you pay attention to the little things.
good luck and have fun