I've been looking at a lot of top laners and I was wondering which one I should buy I was interested in Darius, Fizz, Kennen, Irelia, Lee Sin, Maokai, Shyvana, WuKong, Trundle, Yorick, Vlad, or Volibear. In your opinion who should I buy I'm lvl 29 half way to lvl 30 and I need some good top laners because I'm a top main. I have no budget really just my hard work and IP.
Consider your play style. Are you a 
Zed type player, or someone who uses high skill level champs to take advantage of movement speed bonuses, like Diana?
Or do you consider yourself wanting to try something simple and fun?
Or do you want to add more presence in team fights?
Consider the above questions will make it easier to choose a champ you won't regret. This will also be useful later on when team builder draft and ranked turn on eventually, as it will help you determine your style and presence in the game.
As an example, I wrote on a Word Document all the champs I find interesting in top lane. 9 immediately came to mind. I have in mind 5 to main, and what suits my style best.
To keep relevant, use the similarities in the champs you currently like/use to be a way to predict the NEXT champ you will choose.
Ex. My top Laner must be: -Easy to use/maneuver. -If it has skill shots, they must be long range -Have high damage potential -Have a decent lategame
= Panth, Jayce, Voli, Darius, Nasus.
Hope this helps!
is my personal favorite actual top laner. Though, since top lane is sort of an island now, you can get away with some ridiculous things if you try hard enough. I do 
top these days ;)
