You are right, The JB Hollow 80lb is slightly thicker and stronger than the JB100 Hollow, the 80 is 16 strand vs. 12 strand for the 100
This does not apply for the Solid
I would suggest Seaguar threadlock 50lb as an alternative to the JB60lb, the JB60 is great as well
In my opinion going Hollow is a great option specially for popping as hollow has great shock resistance vs. solid, if you want to go Solid then I believe there are many other brands far superior to the JB solid specially in terms of castability