How would you represent ancestor spirits in 4th edition. I was thinking the Guardian, Guidance and Task spirits would cover them, but having all three in a tradition seems a bit powerful?

Any suggestions?

I would say it depends on the function of the spirit, how and in which funtion your magician sees his ancestors. Remember the spirit of man too.

You mean like Voodoo: which already exists! For your ancestor cult you do do worse than picking voodoo as the template, and changing the fluff and/or drain code around it: perhaps intuition is more important to gain the insight into what the cryptic ancestors are telling you.

As far as I can see every tradition gets 5 spirits. You pick the spirits. Guardian, guidance, task and man are for me the best. It's interesting that other people don't hold the same view, for example my GM thinks (and he has a chance to play with more spirit types) fire are the best. He want's raw fire power (pun intended) in his spirits, I like utility.

Nah, i started a topic a while ago and i am absolutely your opinion, but you will see that your are also right that not many people here share this point of view....strangly.

Actually, in War! there's the Amazonian tradition that only has 2 spirit types (Water, Plant) - one is used twice, the other is used three times.

By correlation:
Combat: Guardian
Detection: Guidance
Health: Guidance
Illusion: Man
Manipulation: Task
Drain: Wil + Int

Bizarre. Well thats War! for you. I haven't bought it yet

In street magic its pretty clear how to make a tradition, but I guess you can deliberately nerf one if you want it. I personally like custom traditions: they add to the fluff around the character YMMV.