Nothing is out of the question, but the 30TW or 50tw Penns will get the job done most of the time.
Your biggest factor to look at is the "what if???"
For instance, "what if you hook into a 300 plus lb mako???"
If you are looking just to fool around with lazy blue sharks, then that real is just fine. I have a video somewhere of myself catching a 150lb blue dog on a 20lb test spinning rod and a 100lber one on a fly rod! (sometimes there are just so many blue sharks around that we have to invent new ways to entertain ourselves while waiting for the elusive mako to show face).
Don't let the smaller size tackle stand in your way of trying.