Congrats on your first century ride, my58vw!

I've had similar experiences in the past on long ride events, never thought about the sodium intake before. I have not had good results with powerbars in the past and now stick to mainly fruit, gels when on the bike. If I need something with more digestive time I would reach for a clif bar. Generally fruit and gels are enough to get to the next stop to refuel with more fruit (or a few cookies). Grapes are my friend.

I also try to have an electrolyte mix in addition to plain water...something like HammerGel's HEED, and sustained energy for longer rides.