A wordpress plugin to find and replace

I'm looking to get a simple wordpress plugin created that I will use to adapt my content for a US audience:
- work on demand on existing posts (and possibly pages too, but posts most important)
- find and replace text in the post - both within paragraph text, within URLs within tags and within the post slug
- have a way I can specify and manage the list of find/replace pairs. I want to be able to manage this in an ongoing way
- the find/replace pairs will be actioned in sequence, from the first in the list
For example, I may want to find all instances of en-gb in URLs in a post and replace with en-us, or I may wish to replace the UK spelling of a word like cosy with the US version, cozy.
I can give further specs and examples of the desired results if this will help.