What exactly are you trying to accomplish? Do you want to be able to shoot things that have engaged your front lines? Do you want mobile shooting platforms who can also assault?
It sounds to me from reading your first post is that you want to be able to shoot, but not be tied down and have some mobility. Gun mages, B-13, hunters and defenders are all good shooting elements that are not required to be static. Stormwall is of course fully loaded to deal pain at range. Stormstrider is nice. Rangers and trencher commandos might be a more mobile force if you are into that. Minuteman is a fun hunter/killer type of jack. Shoot, just about everything in Cygnar has a gun of some sort.
If you want to check our mercs then the Nyss hunters are popular with alot of people.
Check out the
PP forums. They have a nice thread covering all our units, casters and jacks.
http://privateerpressforums.com/showthread.php?7043-Boot-Camp-Mark-II
Battlecollege is OK, too. But I find some of their tacticsa and thoughts lacking sometimes.
http://battlecollege.wikispaces.com/mkiiCygnar