You really should consider using a braided superline....and powerpro is a good one, so is sufix832, spiderwire stealth (I like the camo). I like 15- 20lb test (same diam as 4-6lb mono). The only reason for the mono with a senko is you don't want to spook the fish. To solve this issue I ALWAYS
use a fluorocarbon leader (about 14-17lb test and 6ft long). The Fluoro really helps the bait fall straight because Fluoro sinks. I use a Uni to Uni knot (or double uni) to attach the two lines. It is very easy to tie and here is a link http://www.youtube.com/watch?v=KiO2VvXKkZY
. This will all help with the line twist and the braid and fluoro are very low/no stretch so you will not miss another hook set........Hope you try it.....it will work!!!!!!!!!!