Considering the longer distance you are covering, it's possible an HO version bridge would be useable. The longer the distance to carry the tracks over, the heavier the bridge components (beams, support stringers, uprights, etc) have to be. Using an HO bridge for N scale structure this long would not look too outsized. Use an HO single track bridge and add extra stringers for the double tracks using Plastruct or Evergreen I beams the same size as the HO stringers. This option lets you even widen the space the bridge crosses, say for adding an access/maintenance road along the main.