Will any of the units require additional work?

Units with basins will require plumbing and some might need basic electrical work, but most are free to move as you wish. Wall units will need to be attached to the wall in much the same way as a framed picture is. This is the way kitchens used to be, back in the day. Wooden tops will need to be sealed as soon as possible, how you seal your tops depends on the type of finish you prefer.