I have been playing upright for about 2 years now and realize that string selection is upmost importance. On my 3/4 I have spiracores and I play a lot mainly bluegrass and some rockabilly. I find myself in long jam sessions and these are a little abrasive on fingers. On my 1/2 I have the obligato which I really enjoy but they are already pulling apart at bridge and nut. I was wondering what would be a good alternative string selection for sustain and some slapping. Or how to prevent the pulling apart issue?? Thanks