Pansies and violas actually last quite well as cut flowers. You may have seen them showing up on Instagram in the last couple of seasons as the Japanese have started growing and shipping them. There is no reason we can't be growing them as well!
I don't have specific cultural information, but what I'm hearing is that you need to crowd them in order to get taller stems. I would probably plant them 6-8 per sq. ft, but again, I haven't grown pansies for cutting on any scale. Much like annual phlox, you may have to cut them deep a few times to get the longer stems you desire. The shorter stems are perfectly usable in smaller design work.
These are varieties coming from Italy, marketed as cutting strains. We are selling these as a collection only, not as individual varieties at this time. You will receive 3 trays of 128 cell plugs- (1/2 tray of each of 6 varieties.) This ships as one full box and you need not order any additional items to meet the order minimum.
Order 8 weeks in advance of when you need them. They are available for weeks 48, 52, 4, and 8 only.
Pansies and violas are some of the hardiest annuals around. I would try to give them a few weeks above freezing to establish roots, but they will take a frost without issue at any point in the growing process.