Machine shop would be my pick, but if you had to it yourself, Roloc bristle discs or a wire cup brush would be my pick for the exhaust ports. For the head, you need to take a straight edge and a feeler gauge to check for a warped head surface and don't use any abrasives to clean the block and head.
If you can get the right tools, replacing valve stem seals wouldn't be too bad to do with that head. If that's the case, you can still get the "good" Chemdip that will remove anything that isn't metal. The motorcycle guys have found Lestoil to also work as a dip, if you don't mind a little manual labor.