First, you sell me the intake manifold.

Clean and prep deck is a pain, I plug stuff with bits of rag/shop towel and use a shop vac frequently for crud removal.
An assortment of plastic, wood and metal scrapers and several types of brushes, the goal being a clean surface but no nicks,
especially the piston tops that are softer. Bout the same with the head but more so, since it's aluminum. I've used some gasket removal
goo sometimes on the deck when it looked like it might help, all depends on how bad it is.
At a shop, one will often take an air die grinder with a scotchbrite disk and just buzz the deck till it's clean, and sometimes
the head as well. Lot of folks do a lot of headgaskets that way and get away with it, and it's sure faster. Your call.
Make sure the 3 hole matches what came off it, I use the copper spray HG stuff myself, lot of folks like Hylomar, lot of em
swear dry. I wouldn't do dry unless both surfaces are perfect, and even then I'd ponder it hard.