Just go with a good brand of monofiliment. Stren is good.
For sunfish, trout, other panfish even bass you can go with 6lb test. If you go with much more you risk the fish seeing the line. For catfish you will need a bit stronger set up but even with 6lb test you can catch the smaller ones; if you hook a big cat it will break your line and you will loose less than a dollars worth of hooks , weights and swivels.
Start out with a light spin cast set up and you will be able to catch mostly anything you will encounter.

In fact when it comes to survival; sunfish are a great resource. They multiply like rabbits and will eat almost anything from bugs to worms to even bread balls. you can even catch them with a modest handline such as a spool of line with a small hook. Just bait a small piece of worm on the hook and let it sink slowly; you will catch the sunnies real easy this way. They are the most fun fish to catch and even though they are small and have bones; they are very tasty.