You don't need rig tubing and a leader.
Depending on where you are fishing, do you even need a leader?
Are you casting massive distances or is the venue snaggy?
Shrink tube for hook links basically increases the hook shank and creates a kick for better hooking/presentation.
As for what's best? They're all the same in my opinion except some come weighted or even wire threaded so it's easier to put on.
Also try the search facility there are hundreds of threads about leaders and tubing.