Well, it does depend on what you want your elves to be like -- personally, I'd give mine draconic spells, but I don't see elves as strongly connected to nature. They live in trees, yeah, but that doesn't necessarily mean that they *hug* the trees, too.
But on topic -- if you want to give them a more standard "elven" feel, I think it would be fine to give them a selection of druidic spells, in exchange for some of the wizard spell list. Necromancy could go, for one. I think evocation should stay -- no matter how nature-based you make 'em, I still think they'd have fireballs at the ready. You could swap the summon monster spells for summon nature's ally. I think you could do it in a way that was relatively painless.
As for keeping it straight, with just the regular wizard spell list -- that I'm not really sure about. I know that Magic of Faerun has at least some spells that would fit your motif, but I haven't looked at that in months, so I can't really tell you for sure. Someone with the Spell Compendium should post -- they'd be the ones in the know.