A big one... but you will need an even BIGGER one to put the axles back on...
But to the ops question, I dont feel that those will work very well... You wont be able to get enough lift with those wimpy legs.
The best solution I have found for a TT is to get another set of stabilizer jacks and place them between the axles on the frame and pick up some of the weight off of the tires. SOME not all... This will help take the bounce of the suspension out and help with the shaking/bouncing problem... also works in case of a tire failure you could lift the side of the camper (if you have the appropriate sized jack/stabilizer. )
TV- 2015 Ram 2500 CCLB 6.7 Cummins 3.42 gears
Camper - 2015 Saber 322BHTS