Belgian Wit AG. Please critique

I have put together a recipe for a belgian wit and want some opinions please. It is as follows:

5.5 Gallon batch

4.5lbs two row
4lbs flaked wheat
1lb flaked oats

.5-1 oz Saaz at 60. I know it isnt supposed to have much hop character.

Will probably add a bit of coriander and perhaps .5 oz of sweet orange peel. Maybe more in the secondary...
60 minute mash at 152 and 60 minute boil.

Anything stick out?

A teeny bit heavy on the oats compared to what I usually do for a standard wit (I use about 5%), but generally pretty spot on. What yeast are you planning to use?

WLP400.

How late in the boil should I add orange zest and coriander?

Going classic! I like that yeast a lot.

I'd add your spices 5 minutes before flameout.

Now I don't have a scale at home to weigh my spices. what kind of volume measurements can I use to get me close. I was thinking a teaspoon of crushed coriander and perhaps a 1/2 cup (packed) with fresh orange zest. I want the orange flavor to be upfront and very noticeable although not totally overpowering. I know I can always add some zest to the fermentor if I think it isn't enough.

That will probably get you close. I actually just brewed a wit today, and I think my volumes for spices (I weighed, but just eyeballing it) were about this:

~1/4 - 1/3 c fresh orange zest, with a tiny bit of dried zest thrown in too
~1/4 c coriander, crushed (this is entirely dependent on the variety and intensity of your coriander, so you might want to just experiment a little based on what you have on hand. Mine is very bright in aroma/flavor, but not especially pungent, so I can get away with using a good amount.)