If you don't feel confident with your own rigs, then buy ready mades. Then, when you have some confidence- or results, tie your own! Simple. Also, if you buy ready made rigs, they may not suit your style... imagine having a 10mm bait on a size 6. Argh... Carp are pretty stupid, but if you feel the need to have some fancy popped up, combi, blow back, recoil rig then go ahead if it gives you confidence. In my mind, watercraft is far more valuable that turning into a rig tart!