Are the stinger & other amp kits really worth the price ? I have been hearing bad things about many of them not being true 0 gauge. I have seen welding wire around is it stiff or hard to work with, is there a certain number & type of welding wire to use. I am looking @ amp kits on e-bay seen some stingers for around 100.00 & a few others the cheap ones scare me. Just wondering if they are worth the money ?