Re: best 2-6lb line
You can lose your mind in making a decision like this. The reality is, that most of the lines are mostly the same. The bigger name brands like Stren, Berkley Trilene, and P-Line are all good.
You will find some options available from each manufacturer, mostly centered around materials and "properties" (limp, "castable", color, etc.).
For that weight of tackle, I've have very good luck with regular old Stren monofilament. What I've been doing lately is loading the reel with this line in 4 or 6lb. test, and then using a Uni-to-Uni knot to join the lines, I wind on about 30 yards of 4 lb. Suffix fluorocarbon line. FC line has some nice properties for fishing in small streams (less visible, more abrasion resistant). Using a 30 yard "wind-on" section makes it more affordable to use this line on a regular basis.
I'll change out the regular Stren line every few months. The reality is that it is really on their as a spool filler/backing - I've not had a fish on that class of tackle take me more than 50 yards into the spool, so the knot joining the lines is not a factor. Even if it does come into play, it's a very strong knot, so no worries.