Hi Rick I do some of what your wanting to try. and here is what works for me. My tub rod is a 10' 6 weight. (not important)but the line is. Depending on how deep I need to be, I use a level sinking line in a 2 or the old Hi-D sink rate or the 4 or high speed in a WF (only because they don't make it in a level. Sinking lines are smaller in diamater so level lines cast just fine and your rig is going to go splash any way. Level lines are far under rated in my thought.and in this type of fishing they work as well as any line and cost about 1/3 and if your like me this line will spend a lot more time on the spool than in the water.

Rich