Get Karmian or Demon, whichever is more easily available. High casting speed is always a nice touch when nuking pre-52, and high damage is even better.
You can also nuke with Light Armor if you'd like, although you'll have to chug a casting speed pot before you solo, otherwise your casting will be a tad slow (but not unreasonably slow). If you do choose light armor, and money isn't an issue, get a Drake set. Its Pdef is only a little bit less than Theca and it provides a nice Mdef bonus.
As for weapons and playstyle--
Nuke. You're nukes still deal decent damage at 52 and don't fail often.
If money is an issue-- get a mid-C grade or mid-D grade weapon and nuke, as long as that weapon is 2x bsps consumption. It will save you a lot of money. I used a D grade staff of magic until level 46, and then switched to mid-C grade crystal staff.
If money isn't an issue-- get the highest Matk weapon possible and nuke anyway, and get a Demon set. Keep in mind, especially at level 45 and before that, you can spam Aura Burn and not even have to use your uni.
What type of armor you get depends on where you fight, your personal preference of fighting style (and coolness factor!), and your budget.
As a very poor ES, I chose to spend a lot of time soloing in Ivory Tower and Enchanted Valley. The quests and load of spellbook drops there was well worth the effort. The downside is that many of the monsters there are magic resistant. I mostly meleed along with my summon (soulshots optional) in my borrowed plated leather set and a pair of duals I slowly upgraded to top C.
If you have a bigger pocketbook or just want to level fast, nuking in robes is the way to go. Most of the magic coins quest monsters are perfect for nuking. Karmain or Demon set prefered. As stated above, you can nuke in light armor as well, but you'll have less casting speed and mp.
An SAed berserker blade, if you can stand using a 2H sword on an elf (but then, if you are willing to use duals, you obviously don't care much about visuals), is better than focus duals.
An SAed berserker blade, if you can stand using a 2H sword on an elf (but then, if you are willing to use duals, you obviously don't care much about visuals), is better than focus duals.
Both duals and 2 handed swords look awsome on a light elf! Then again, everything looks good on light elves... ^_^
Demon set, over enchanted homu sword. Just level like nuker till 52 and use your pony to recharge yourself when needed. After 52 switch to light armor and get kris or focus duals.