The above post is correct on two fronts: a 6 element lens is preferable; and you should be able to find real good bargains on the used market.
If you are happy with the El Nikkor, a six element 80mm would do you well. I use a Rodenstock Rodagon 80mm f4 for MF printing. Schnieder makes a 80mm f4 Componon-S which should be a very good lens.
But if you can get a real good buy on a APO lens from any of the manufacturers, go ahead and grab it.
gene