So I play alot of Ryze/Singed, Mostly because I find they are good on most teams. Not to often is it a bad thing to have MORE Burst to really sway team fights with Ryze. Or In Signed case, having someone who can initiate tank and dps never hurts either.

With Zilean If i play him alot will I have the problem where I not should pick him, because it is just a horrible team setup?

It will be rare that you have this problem, because zilean is strange in that he fill two different roles during different parts of the game...

At the beginning thru midgame, he is a nuker like ryze/annie/etc and will be able to put out huge damage that way, but at the end of the game he doesnt scale quite well enough to be an end-game caster carry (like karthus, kennen, Anivia) and becomes a support role, making your dps chars unkillable.

Basically, he will work on almost any team because every team has at least one DPS character (meaning having zilean is a good thing) and he can still fulfill the mage roll for your team if there is none

What xahhfink said. Zilean is a support champ first and foremost, and there's almost always room for a support on any team.