Hexcrawl [Part 2: System]

I'm planning to cobble a system together for my hexcrawl campaign, since there's no single gaming system that does everything I want it to, so I'll be looking at the different parts that my gaming system needs and what I'll do to fulfill that need.

Combat: I'll use 4th Ed. for this. I like the combat system, which is more than I can say for 3.x, and the ease of building encounters will mean I can focus more on other things.

Magic: Magic is an integral part of fantasy roleplaying. I've been a great fan of Vancian spellcasting in my rpg's. The resource management imposed by it means very few wizards would use their spells outside of direct adventuring, which always seemed a waste to me. After all, if you have the power over reality, would you use it to do nothing but sow death and destruction on your enemies to exclusion of everything else? I know I wouldn't.
Which magic system I'll use in place I don't know yet. I like the Ars Magica system, which is flexible enough for my liking. However, there's nothing to prevent a wizard from using, for example, Perdo Corpus to kill his foes in combat. I could rewrite all the wizard powers so they're the equivalent of the Ars Magica action/substance combinations, with a minimum skill requirement, but that's more work than I really like, even taken into account that no single wizard would have access to every possible combination.
For now, I'll keep my eyes open, in the hopes that something turns up. If not, I'll grit my teeth and use Ars Magica.

Skills: I'll be doing away with skill challenges. Never liked them much. I might not use the normal D&D skill system at all. I might invent my own system. For some reason, this is the part of any gaming system that I have the least difficulty tampering with. More on this in a later post. Suffice to say that'll it have to be simple, so as to fit in with both the combat rules and the magic rules.

Mass combat: I'm not sure I'm going to be needing these rules, but I'd like to have them handy. The most elegant ones I've seen so far are in the Lord of the Rings RPG by Decipher. They're simple and general, leaving place for individual combat where dramatically appropriate, so I see no problem stealing them.

Apart from these elements, I need only random tables for all the following:
Terrain (probably, depending on which of two different starting points I use)
Weather
Encounters (different ones by climate, terrain and civilisation level)
Events (in case my players decide to become rules)

Next time, I'll elaborate on how I'll implement skills.