I've never had luck keeping mock orange bloom in a bouquet and I've never known of anyone forcing mock orange. The best thing for forcing would be either forsythia or quince. Their is a low growing, spreading forsythia which seems to bloom later than regular forsythia and holds its blooms longer. Also, there are now white, pink and peach colored quinces in addition to the old red, which are beautiful in a mixed arrangement. Ornamental peach trees are often forced into bloom in Asia to celebrate the lunar Chinese) New Year. They are very pretty. Ornamental crab apples (Brandywine)are very pretty as well. These are small trees. An early, early bloomer is winter jasmine. It doesn't have a fragrance but it is a low grower and blooms yellow over a long period. Finally there are the purple tulip trees which bloom later and are less likely to be killed by frost. These are fragrant. My favorite would be the forsythia. There are so many REALLY GOOD varieties now.

I do love quince. I vote for that. I have two.