Ready made rigs are usually designed for pole fishing, you’ll be using a “long line” on a whip, with a 4m whip you’ll need 3m of line, this allows for and 18” hooklength still bringing you 18” short of the whip length, this allows for the bend in the whip when swinging a fish to hand.
Ready made rigs also come with pole floats attached top and bottom, I prefer a small waggler or Drennan Stillwater blue attached bottom only. Really easy to make your own rigs and a lot cheaper too.
On the subject of line, through experience I found using light lines e.g. 3 to 4lb troublesome, the line often wrapped around the tip on casting, I now use a stiffer length of 8lb fluoro with a longer 24” hooklength that may vary between 2 and 4lb.