I don't fish much anymore, but I usually go with 10 lb. test and find myself reaching for trusty Stren when considering an all-around line like that. If I expect to run into gar, I would just get wire leaders. For my smaller, collapsible rod and reel that fits in my daypack, I go with 6 lb. test.

Maybe there might be a more up-to-date angler out there with better advice for you, though.