I think, with a little tinkering, you just might be able to find that 12' #4 you are looking for.
I know of a rod builder (designed Sage's finishes) that is in his late 80's that does wonders with rods.
You buy a 4100 XP blank (which is softer more progessive XP) and have him splice in a butt from some other blank...he then buiolds up the rod and voila!...you have your 12' #4 two-handed rod!
Ryan S. Petzold
aka Sparkey and/or Special