it can be done in a day. I had never seen any internals to a Subaru before and did mine, no helper, in about 5 hours - with several breaks.
your part numbers are the numbers on the exploded diagrams. you will need to click on the part number in the list below the drawing to get the actual Subaru part number for the order.
the crank seal is part #13 on this diagram:
http://www.subaruparts.com/diag/?mod...category=032-A
there are trivial things like antifreeze, etc. If your hoses aren't in good shape you might want to replace them. Both upper & lower radiator, plus some little hoses here:
http://www.subaruparts.com/diag/?mod...category=035-A
last, you need a special wrench or at least a crow's foot for the PVC (search or in How To files).
good luck