Javax, the entropic squid's page

So, my questions comes from the fact that there is no such thing as a 10 bulk armor or weapon (unless you take something stupidly big like starship weapons or vehicules). This brought the question "can the created armor have an upgrade?" This would raise it's bulk value, by extension this brings the question, can you summon an upgraded weapon.

So I just stared skimming through the first book and I could not find any number written in bold telling GMs how many players are expected.
Google was not much help either.

This would be my first official Paizo campaign, any advice on this topic?