I've been an advocate of ditching the wire leaders when hits from toothy species are unlikely for some time.
There's nothing in what follows that I haven't posted on here elsewhere but as it's relevant to this topic and might be helpful, I'm going to reproduce some advice that I recently sent via PM.
A 24" (40cm) leader sounds about right but I agree that cable and the big shinney swivels and clips that go with it are likely to spook fish.
Flouro or mono is the way to go.
On the outfit that you describe, I would go with 40 - 50lb flouro or 50 - 60lb "hard" monofilament.
If you go with flourocarbon, you will find it's thinner than the equivelent mono, more abaision resistant and obviously has optical advantages as well - but it's pretty expensive stuff.
With flouro, don't be tempted to buy the stuff that's sold as a mainline (especially Berkley Vanish as it'ts rubbish) and go instead for the stuff made by Seagar or or similar companies and formulated as a leader. This is usually only sold in 25m spools and as I say it is expensive - I wince every time I buy a new spool.....
If you go with mono, you want the cheap stuff. Nylon basically has two formulations, the expensive stuff is soft, limp, easy to fish with, has low "flash" when the sun gets on it and is relativly expensive. The other stuff is cheap, springy, has a "hard" (read abraision resistant) finish and is horrible to fish with on a reel. These very qualities make it a great and very cheap leader material - - it's what I use when I'n throwing lures into the rocks for barramundi.
When it comes to attatching your leader to the braid, forget swivels (they will eventually knock the liner out of your tip ring if you fish in the dark) and join the lines with a double uni knot
http://www.wonderhowto.com/how-to-tie-d ... 5798/view/
Make about 11 or 12 turns on the braid side of the knot and about 5 or 6 on the mono side to take account of the difference in line dianeters and get a balanced knot.
On the other end of the trace, you will need a clip. For me, the Rolls Royce of clips (and I know they are available in India) are breakaway fastlink clips. Just tie it on the end with either a uni knot or an improved clich knot and you're good to go.
Don't forget to check the leader after each fish and shorten it down a bit if it is getting badly abraided.