Or a Vilano-trained Flambeau who, instead of tossing rocks at opponents, instantaneously builds about-to-collapse cathedrals around them. Equally effective at bypassing magic resistance, but far more stylish.
Note that Rego Corpus craft magic (aka "instant surgery") tends to be quite a bit higher - in the 25-30 range. But has the benefit of not needing to use vis, as opposed to its CrCo siblings.
I would be curious to see that construction of Spell which base of ReCo do you use ?
And by 25/30 you mean Spell level or finesse ?
I assumé like a Profession Craft you need your Chirurgy and medecin ability at 5 in order to do some good work.?
p103 of RoP: Faerie for the generic Faerie God Blood.
Fafner and Fasolt were the two giants who built Valhalla for Odin. So quite appropriate ancestor for a builder of great thing. It also comes with a nice background and possible story as Fafner killed is brother later on, and finally, consume by greed turned himself into a dragon hoarding treasures. So, if you take this blood, you know what's coming to your character if he starts to follow his ancestor's path :mrgreen:
For the explanation of the whole +4:
Magical Surgery is discussed in Arts&Acadame, on pg. 60. And basically - yeah, it's ReCo craft magic. The Finesse roll is Int+Finesse, equal to the surgical difficulty +3. (Of course, the surgical numbers are ALSO listed in A&A, on pg. 61 - so not much help for you.) The surgical difficulties are anywhere from 3 to 15, with most being in the 9-12 range.
The spells that go along with those rolls are anywhere from 5 (trivial surgery) to 15 (major surgery) to 25(life-saving surgery); you can also do DAMAGE with ReCo surgical magic, as well. For more information on ReCo guidelines for surgeries, see the Big List of Collected Spell Guidelines,at http://www.atlas-games.com/pdf_storage/ArM5Guidelines.pdf
It should be noted as well that ReCo surgery is not a way to instantly heal wounds, just to patch them and treat the wounds. Which compares to CrCo spells which boost recovery rolls already without Vis or the chance of injury...
I like these three options for healing:
CrCo non-ritual: increase drastically your chance of healing, without sequel, but take the same time as normal healing.
ReCo surgery: more or less instant healing, but with the same consequence as surgery.
CrCo ritual: almost instant healing (minus the ritual time).
You have three options: cheap, fast, without consequence. You can only pick two 
.
Each as a trade off, nicely balanced.