for short jumps I like my old lucasi jump stick. Have replaced the ferrule/tip with a once piece I got from MasonH, but it worked just fine before that.
Can jump, depending on cloth and cue ball, about 2 to 3 chalk widths apart pretty easily. Any closer than that and I'll kick the ball because its a higher percentage for me.
Longer jumps I use a j/j jump break, and jump with the full cue. Its easier to control. My j/j has been lightened up a good bit. Best jump cue I've owned was a varney j/b cue in all honesty, was a really light cue. Was under 17 oz and I could jump full cue, or with just the jump handle with ease. Broke great too. I had another one of his, and hated it, but it was heavier.