I use 15lb mono with a 50lb shockleader for spodding. In fact I use 'last years' mono which I wind off my fishing reel onto the spod reel, then tie on new shockleader.
As for marker reel, I use the same type of reel for marker as I use for my fishing, admittedly a 7000 Beastmaster, but for years it was an old Shimano 4000 size baitrunner, same size as I used for fishing. That would be equivalent to a modern 6000 size baitrunner.