Support wizards

Im building a list around Skrag my question is when it comes to support wizards what is the best choice. We have discussed the skrag double firebelly list. I am stuck as whether to choose beasts or heavens. We can all imaging the carnage unleashed by skrag having savage beasts or wyssans on him putting out up to 14 strength 8 attacks. But Lore of heavens is appealing for harmonic convergence and curse of the midnight wind. Comet is always good. So my question is what would be the best choice

You are playing a in your face special character that needs to get in combat. While Beast is the obvious choice to buff him as much as possible, the high casting value of some spells mean that they will be hard to cast on a level 2, especially since you won't have that many dices left. Heaven's spells are probably easier to cast for a level 2.

Try both! I love Beasts but it is true most of the buffs would require 3-5 dice to reliably get off with just a level two. Heavens would be easier but I would personally have a Firebelly as my backup.

Heavens. A Firebelly can help though with chaff harassing and so on, but I find that Heavens has the chance to do a similar job. It is a bit dependent on what you roll mind.

Chuck on Grut's Sickle if you're happy to forego the dispel scroll. It'll let you save a few dice for spreading out more spells.

For backup purposes I think it's hard to look past the Heavens caster.  -1 to hit Ogres is just awesome.  Of course if you don't plan on taking any Leadbelchers then a Firebelly certainly deserves a look in as well as he could provide the anti-chaff support that the army needs.