You only want a 6" wide kitchen cabinet? Good luck with getting anything in a cabinet that small. The only way I know of getting a cabinet of that size is to have it custom made.

Most of the kitchen cabinets in home center stores - even the brand cabinets displayed in the stores, can be ordered unfinished. See if they have something. Look for maple if you are painting as it paints well.

Thank you! I do appreciate all of your advice. I was hoping that someone could supply a "source", as I had already gone the route of your suggested ideas, before I requested help. Ultimately, I would just like to find a cabinet that doesn't have to be redone or reconfigured. Thanks again.

Thanks, I have seen those, however I am looking for a cabinet.

$300-$400 and a custom cabinet maker and you might get close to the existing door profile. You're gonna run into a product order and labor minimum to deal with any of this. Almost any semi custom cabinet line has a 6" tray base cabinet. Or wine cabinet. Or 6" filler pullout.

A better choice would be to design away the need for this. And get handy enough to DIY this if you can't do that.