SureAI

I'm about six and a half hours into the game and ready to accompany Jaspar to Ark, but I'm still stuck with an iron sword--a mildly enchanted one, but a bottom-tier iron sword nonetheless. Sura doesn't sell anything better. Can I find a better sword somewhere near Riverville? Are they scattered around the world Morrowind-style?

Have you done Sillas's quest at Riverville? You can find a 2H Cold Night sword. Most wild mages have a silver sword. You can find some in the tower south of Riverville but I don't recall their weapons, you have to swim across the river to the path south of the Myrad tower and head south. (Just went there to check, the wild mages had silver swords and also a fireball staff.) Once you get to Ark there are many more possibilities.

Unless the player is already at a decent level (doesn't sound like it) or playing at a real low difficulty, I wouldn't go anywhere near those towers.

How much did you explore the Sun Coast? This is the easiest region and there's quite a bit of loot and experience to gain there. Having the game simply lead you on the main quests will be too frustrating since in all, they will only cover about 1/3 of Enderal and you will miss out on a lot of stuff, especially if you want to find better weapons and armor, as well as have the gold to buy the skill books.

if you level your handicraft high enough (might require a good few levels to accomplish tho) you can eventually craft aeterna weapons which are the best weapons in the game aside from bound weapons but at the same time can be just as powerful due to being enchantable while the bound weapons obviously are not.........

also keep an eye out for bluprints as well not just for weapons but also for armor as they would be extremely valueable in increasing survivability early on

as a side note if you plan on dual wielding i would recommend for enchants to have a weapon for each element (fire/frost/shock) and another for soul trap tht way you can keep your weapons fueled without as much worry of running out of soul gems as they are pretty inexpensive to buy with high enough rhetoric level and are a semi common mob drop