90% sure they don't make ls3 engine mounts for the lancer. As everyone else has stated its going to cost alot of money. But I won't discourage you, if you have that kind of money to spend(which is going to be a ton) I'd say do it, cause I think you would be the first one to actually do it. If you decide to go through with keep us posted because that would be a mad build in more ways than one.
We briefly touched base with this topic on LancerNation (FB) and I was just wondering if you guys re-flash the ECU back to stock if she gets a trip to the dealership to maintain the warranty? My knowledge on ECU Tune is very limited and you mentioned something about an e-tune since we are miles apart.