Doesn't it mention the Ra Cailum has 12 Jestas and 5 Cannon Option kits?
Yes, more precisely, it says that 12 Jesta were deployed during U.C. 0096 for evaluation purposes and assigned to the Londo Bell's flaship Ra Cailum; among the spare parts for these units, 5 Jesta Cannon use option part sets are included.
Concerning the weapons, here's an incomplee (and mostly free) translation, from top left onwards:
Beam cannon: this high output beam weapon mounted on the extra armor of the right shoulder is directly connected to the generator. such an arrangement avoids energy supply drops, thus allowing a regular rate of fire.
Being also linked to the high performance sensor unit installed on the head, this weapon can be used efficently in middle-range support.
Hand grenade/grenade launcher: the hand grenades (throwable weapons) mounted on both hips of the MS are also stored on triple grenade racks along its legs. They have a great desrtuctive power both when launched simultaneously and when used one by one.
Beam rifle/grenade launcher: this is a customized beam rifle characterized by an enlarged frame and an alignment device placed above the barrel, used for higher firing accuracy. Below the barrel a grenade launcher is attached.
Shield: this customized shield (the same used by standard Jesta units) is connected to the backpack of the MS thanks to a special arm unit.
4-tube multi-launcher: this multipurpose projectile launcher mounted on the extra armor of the left shoulder is an anti-MS weapon.
Beam saber: standard close-combat weapon. They can be stored on both forearms (just lake in teh normal model) or, alternatively, on the hips. In this latter case, the right forearm mount can be used to attach spare beam rifle magazines.