@Jamesmor At minimum you may want to pick up the Occuld weapons as they are all-class weapons but are also decent for our current content.
Going ahead you definitely want to pick up the Atlas EX, Lightstream/Trailblazer, and Liberate weapons to have some variety and some options of what you can be using. These weapons are all limited in their resources as you can currently make about four Atlas EX weapons due to the Chronos Eternistone (upgrading a Val weapon to +35, having completed the previous Mission Passes that awarded it, reaching a specific number of titles, and completing the Episode 5 story and I believe about three Lightstream/Trailblazer weapons (completing the previous Mission Pass, and fighting Dark Falz [Persona] ten times, and another for fighting Dark Falz [Persona] fifty times). In the new Mission Pass we will get the Liberate Unlocker/Key Rivalate that will let you create the Liberate/Rivalate weapons.
If you have not done it already, there is a free Atlas EX Gunslash given out by completing five Recommended Quests (and getting the present boxes) which gives you the resources needed to category change it to any weapon type you want by talking to Zieg and going to the "Change Weapon Category" menu. You can also get the Ofze set of units by completing the Limited Quest nine times on any difficulty so you can at least have one end-game weapon and a very high-level of units.
Both the Atlas EX and Lightstream weapons will remain highly relevant in Episode 6 with a future upgrade though the Lightstream weapons may start to fall off in power in favor of becoming a PP Battery for you (upon dropping below 10% of your total photon points its potential replenishes all of your photon points with a cooldown of 120 seconds before this effect triggers again). Going ahead you definitely may want to consider picking up a compatible Genon weapon for use as a PP Battery as it can utilize two potentials (S2/S3: Lucent Adversity) which will drain your health with the use of techniques/photon arts but will also greatly restore your photon points so you can easily get back up to full photon points to keep up in combat.