I am looking for a patch/game that is Soul Silver or Heart Gold that doesn't change anything but the wild pokemon. I want to be able to catch all pokemon in the wild. Not exactly all 400+ just the nore 252 that were in Johto and Kanto

Is there any rom out there that has this?

It can even be Firered and leafgreen.

I have exhausted the search on here looking for it... but, If I missed something obvious I apologize.
I may have to make it myself, but I thought I'd check