In order of what seems most appropriate for their society, culture and alignment, I think the Bard, Sorcerer, Ranger and Druid are the most 'Elven' class options (with classes like the Duskblade, Beguiler, Swashbuckler and Scout also fitting well, from later books).
Wizard? Not a chance. About as likely as Elven Monks, which is to say, they could certainly exist, but they surely wouldn't be the majority! With the removal of their 1st and 2nd ed magic resistance, *Dwarves* fit better into the Wizard class, thematically (and Gnomes, to a lesser extent).
The Bard really seems the idea Elven favored class, combining the D&D elven focus on lighter armors (elven chain), bowmanship and swordsmanship, artsy-fartsy stuff and innately magical bloodlines. It's like a built-in fighter / magic-user class, which is basically the role that the D&D Elf has always been cast in.
As for the Con penalty, I've never been too fond of giving any PC race a Con penalty. It's just too brutal at the lower levels. A race that is naturally sicklier, weaker and more prone to dying of opportunistic infection, or perishing during extremes of weather, drought or famine than everyone else (including every animal in the Monster Manual, even the Tiny ones their wizards use as Familiars!) probably should stay in their hermetically sealed bubbles and not go adventuring, let alone live in the woods.