Engine swap will require lots of details. Apart from fitting the new engine in, it will weight a lot more so expect to have to get a new front suspension set up. And it will drink a lot faster, so you will need new fuel pump, and it will blow out a lot harder, so new exhausts will be needed. I know doing the actual swap in old chevrolets are relatively easy for all its worth.
You will run into legal issues regarding the 10" fronts and 12" rears. Unless you find a set of wheels with crazy offset, you will need wheel spacers which aren't legal. You can't alter the wheel track by more than 25mm total and you can't run tires more than 30% wider than original. I checked this out with the RTA (its in VSB 14). The most frustrating bit is if you do choose to just do it, it will actually void insurance aswell.
Power windows can be retrofitted, there are both specific and universal kits around.