Weapons
Magi can wield any weapon in Tearron, even ones that use gunpowder. They may not be as effective or strong as an Aaditan warrior when it comes to sword, or as good of a shot as a Gunwatch, but there is nothing stopping a magus from learning hand to hand combat. They may be more partial or inclined to use smaller, more accessible weapons, such as staves, shortened pole arms (glaives, spears, halberds, etc.), daggers, ranged (bows/crossbows), anything that will leave an arm free for casting and keep their enemy far enough at bay. Voyeants are a major exception. Due to the nature of their powers, many become very familiar with short ranged weapons.
Most, if not all magi in Briand only carry what's given to them by their house, or the Cossentines, which means they are the most limited in what weapons are available to them.
Aaditan magi have a wider variety to choose from, but they do not have first choice of the weapon cache there. Aaditan born warriors take the best, but magi are welcome to bring raw material to the smiths for better weapons.
Riders, Provosts and Duennas of Santori have the best weapons a magi can find, and for good reason. Most own relics of the Spire, or even Argall, though almost all weapons from Santori are enhanced or enchanted in some way.
Armor
This varies from magus to magus, depending on what magic they use, and what role they play in Tearron.
For example, Riders from Santori are free to pick their choice of armor. Many seasoned Riders wear relics from Spire, or even Argall, but these are rare (and require admin approval).
Magi who have been married into Higher Houses in Briand will rarely be seen wearing anything other than house colors on fine clothing, but all voyeants in Briand are required to wear full armor, and keep their skin clothed at all times.
Those in Aadita tend to look more savage and wild than any other magi because they have adapted their carefree attitude towards outward appearance.