welcome to the forums! hmmm, I thougt everyone knew an SE had a 3800 option...hmmm.
anyways with regaurds to your SE. It is VERY simple to change an engine out in these cars. I'd check the oil and see how gummed up it is. if it isnt, you are saved. changing the head gasket is a simple process that should only take 4hrs or so. It can be a very reliable car! where are you from? if you feel you do not want to deal with the current engine in it, Ed Morad can get you a engine with low miles for CHEAP!