Eve client uses pretty much the same amount of resources as a WoW client, maybe slightly less memory and a bit less intensive, but you can really ramp the gfx down in that game just like WoW. However, I'd leave at least one of them maxed out because the game is beautiful.

I'm not aware of any active multiboxing corp. I know a few multiboxers have their own corp, and that is the route that I went. It's incredibly easy to create your own, and isn't retarded like WoW requiring signatures.

Eve is different to multibox in that you rarely ever use your keyboard, it's very mouse intensive - there are hardly any keyboard mappings in that game, a damn shame. But you'll get used to it and some people have had success with ISboxer and video streaming/repeater regions. I just multiboxed the old fashioned way (no software whatsoever) when I mined and it worked fine.

If you can afford it, I would get run as many accounts as you can afford. In a perfect setting I would have a group of miners and a group of missioners, all on separate accounts training at the same time. Since you can't train skills on multiple characters, you would have to alternate skills on your miners and missioners.