Where is the 'standard package' detailed? I've looked in the supernatural powers and spellcasting section, but I can't find it. I'm wondering if this is something added after the pre-order version?

Your story pg 287-292

EDIT: And another question... If a character already has evocation and accepts Seelie magic, the cost for Seelie Magic is then [-3]? [-1] for tacking on the power source to Evocation and an additional [-2] for the Seelie 'ritual' component?

Base cost for sealie magic is 4, you get a discount of one for already having evocation bringing it to -3.

I think your looking at two different levels. what i will refer to as mutations and permanent alterations.

Mutations, are an instantaneous affect that through damage alters a part of the persons body these should be fairly simple, relatively permanent on a human, and are in the grey area. Examples would include

Fatter  curse the person in such a way that they dont absorb nutrients properly, thus they grow fatter.       
Skinnier  As above           

New face   This will *not* be pretty. you'd be looking at things along the lines of breaking there nose, useing blunt trauma to reshape the skull ect., you'll need an extreme consequence.                   
 
New fingerprints  Easiest to simply remove them entirely via fire.               
 
New hair You could probably cause it to grow more or less, or make it white, anything more is verry probably a law violation.                     

Permanent Alterations
12 complexity to go from the standard thaumaturgical starting point of a day to a mortal lifetime. So thats your minimum. You will need another 30 to ensure it works, as all of these require extensive reworking of a persons body and thus invoke the section in your world that says that altering another person is the same thing as killing and remaking them.

I would agree with bitterpill, mechanically the easiest way is to just use sponsored magic for it. the themes of it is "whatevers in the circle"

fastest of spells taking a
minute or more..."

How long is an exchange in combat? 3 seconds, a minute, ive seen systems that span that range.

What if you have thaum at evo speeds from sponsored magic? can you then just say that you need to have the complexity and can cast it it "combat rounds?

The book is tragically vague on these details.

Channeling [X] thaumaturgical grouping with evocation's speed and methods would be the most obvious benefit
ie. what the book calls the 'shell game'

Using the current iteration of the system we've come up with you'd be looking at.

Ability to take sponsor debt to invoke an Aspect for spellcasting without spending a Fate Point [free]
Access to Channeling for sponsor's element [1]
Specific types of thaumaturgy at evocation speeds [1]

With the standard reduction if you also have thaum/evocation.

It would be described as something like
Dresdenian Pyromancy  
Having tapped into the terrifyingly great wellspring of fire magic that is Dresdenian Pyromancy you can cast fire magics with unparalleled scope and breath.
System
The character may use Dresdenian Pyromancy as the element of fire for the purposes of evocation, as well as cast any form of thaumaturgy that incorporates fire as an integral element with evocations speed and methods. The character also receives 4 focus item slots if he does not already have thuamaturgy or evocation, reduce a appropriate if he does.

As to cost your looking at something like 2, possibly more depending on how highly you value the focus item slots. Personally using this example i would reduce the focus item slots it gives to 2, give it a base cost of 2. explicitly state that the 2 focus item slots are the ones you'd receive from evocation, meaning that you only get a -1 to this power if you latter pick up evocation and call it a day.

I would say you've got a couple of different sceneries

1] The persons mind is permanently gone. the transforming character gets lawbreaker, the killing character does not.

2] the persons mind is not yet completely gone. Both get lawbreaker.

3] The persons mind is permanently gone, the pc tries to turn him back. The one who first changed him gets
lawbreaker, the one turning him back does not but will probably mess it up as biomancy is hard.

4]  the persons mind is not yet completely gone, the pc tries to turn him back. The one who first changed him gets
lawbreaker, the one turning him back also gets lawbreaker.

So if it was JUST channeling the cost would only be [-2]?

What *exactly do you want it to do ren? if literally the only thing you want is channeling for x element then just buy channeling.

When i run i make sure that at least one character gets compelled every scene. I've found that making fate points readily available makes players much more comfortable with spending them for declarations, and gives them a much stronger feeling of helping to tell the story.