On the same side quest where you get Karla, check out the shops. Any and every weapon is available. If you have Jaffer, you might want to get a few Killing Edges and any type of Weapon Triangle Reverse Weapon as well as Killer Axes, Lances, and Swords. There are also Silver Weapons. It is recommended that before you go in, that you take four of your soldiers who can use different weapons and trade their items away. Units on horseback are desirable. Then, take a total of how many and what kind of Lances, Swords, Axes, and Bows you need. Next, take the four soldiers that can purchase these weapons and have them stock themselves with the number of weapons needed. Before the next Chapter, trade all the weapons back, then trade the ones you purchased away. You do not need to worry about money, as Hector withdraws a a lot of money from the treasury before the mission.