How are you on standard Japanese?
んち is just verbal shorthand for のうち. I encounter it where I live in Gunma, which is nowhere near either Osaka or Nagoya.
That answers my first question....
Do you not know what 見たかった means without the わ?
The ending is used typically only by female speakers in the Kanto area.
Devote your efforts toward learning the fundamentals of standard Japanese before you spend much time worrying about the finer details of regional variations.