i don't know how much experience you have with body work but the best option is going to a junk yard and cutting that section off a car and replacing it completly. from this angle i doubt any body shop will try saving the Fender
. i would look for a smaller family owned body shop to get the work done in my experience they are more willing to work with you and they also do a good job. also remember your car is at least 11-12 years old if you haven't already replaced the timing chain then you might just want to save up and get a newer one with less miles and swap the mods you have already done.
defiantly check out your local junk yards the ones near me have a good dozen of the early celicas