All the above mentioned all work well, the GSP and the GX2, however I have used Roman Moser Power silk, it is very strong in fact you can't pull too tight or you will cut the hair completely. A gentleman by the name of Tom Steinberg, a truly fantastic Deer Hair specialist turned me on to 4lb Fireline. Of course you will have to spool it onto the bobbin, but it is fantastic and based on price cheaper than anything else. Strong as hell for spinning or stacking .
Odive" Vio Mon aime!!!