The Calibur line of swords is great - they're very well-rounded. Good damage, really nice charge attack, decent speed. If you're going for the Leviathan Blade, that's a good choice already.

For bomb choice, you might consider a few different ones depending on how you intend to play - for soloing, the BAB or equivalents (Nitronome for example) would be good - normal type damage, big blast radius, knockback. Obviously weigh up the charge speeds when choosing as well. If you're into party play, the knockback effect may be problematic. The Atomizer line of bombs are generally considered as excellent party bombs - you can choose to go with Fire (dps), Freeze (CC) or Poison (Heal reduction/enemy attack power reduction).

For shields, the Owlite line is popular because of the elemental defense and (mainly) fire resist; it also has decent levels of normal defense and health. I wouldn't worry about shadow damage at this point - it won't figure into T1 content, and rarely figures in T2. Look into it more in T2/T3.

In terms of armor, you want to go for pieces which enhance your style of play and/or mitigate the damage you take most. For example, the Skolver/Vog line is great for sword-users (Attack power/Speed increases). Other armor sets are favourable for providing resistance to certain types of damage, so plan accordingly. If you're diving into a gate with lots of fire strata, guess what sort of resistance you're going to be wanting? Mainly though, I would suggest learning to use your shield properly as that will soak up a lot of the damage. Most of the damage in the game is avoidable, either through dodging or blocking.